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Documentation Style guide


Ideally, all AROS documentation should share a common style, regardless of the intended audience of a specific document. While first-time contributors can't be expected to adhere closely to the style in use, all documentation should eventually be made to implement a single style.

This document lists a number of guidelines for our documentation, both in text form and for the web site. To the new contributor they should give an overview of issues that could influence the style of his text; for those regularly involved with documentation and translation they should provide a mould that documents could be formed with. Hopefully, it will in time grow to be a full-fledged style guide for AROS documents.

This document focusses on the English language versions of the documentation, as that language is used as the AROS default. It's expected that eventually translators for other languages not just translate this document, but substitute and add language-specific guidelines that suit the needs for their language.


We have to take care to create documentation that can, in it's text form, easily be read by all who work on it. This influences the characters we can use, until AROS gets Unicode-support, as well as the text width used.

ISO character set

Our English language web-pages are encoded as ISO 8859-15. It'll probably make life easier all around if you set your editor to that same set when working on English documentation, if possible. Of course, if you have no need for characters beyond the ASCII set, any ISO 8859 set will likely suffice, just don't forget that limitation. For other languages, the same will holds, though in some cases with a different character set.


Several characters are available that could be used as apostrophes in our texts. To avoid a chaos of apostrophes, we've settled on using the ' (decimal ASCII code 39) only. Other possibilities, like accents, tend to be asymmetrical, which doesn't work well for punctuation that should hang in between two letters. Don't use those.

On the other hand, ReST uses back ticks for a number of purposes. Do not confuse the two.

If you use a word processor, rather than a text editor, check that it doesn't change the apostrophes automatically to accents or non-supported characters. Also, take care not to use asymmetrical aligned quotes as apostrophes.


  • Spacing is 1 space, also between sentences.
  • Don't fill out lines with spaces between the words. It makes the lines less readable in the text, and on the final page they'll likely be ignored.
  • Trailing spaces on a line are not visible, and can only confuse editing. They should be removed.
  • As with code, indentation is 4 spaces per level. An exception is made for lists, where indentation of four spaces would separate the leading symbol too much from the text it introduces. Lists therefore have their natural indentation.
  • Spacing between sentences could be set to 2 or 3 spaces. Note that this is only for the readability of the text version; it doesn't influence the final pages.
  • We could use 4 spaces for lists as well, if ReST can handle it, and accept the distance for "+ The text".


Tabs, tabulator stops, do have some functions in text, but can also cause problems.

  • Tabs are not used for indentation. Even when including code that requires indentation by tabs (Make files), those tabs are replaced by spaces in the text, so there will be no side effects when the text is processed into a web-page.
  • Trailing tabs on a line are not visible, and can only confuse editing. They should be removed.
Do tabs have a function in our documentation at all, or is it better not to confuse ReST processing with them?


Ideally, the spelling of each new document and each revision would be correct to begin with, and most contributors will have spell checkers to help make that a reality. Perfection is hard to come by, however, and we should expect corrections made to the language of documents. In this case, differences of opinion are possible about what is correct.


With people from different locations contributing, it's nigh-unavoidable that different dialects of the same language will be used in the same document. At least where spelling is concerned, try to adhere to the spelling that was used when the document was created or, when viewing just the current document, the spelling that most of the document adheres to.

Decide on a standard dialect for each language. This would preferably be the same choice as for the locale languages, if this has been done there. Each writer would have to try, to the best of his ability, to match that standard, even when that dialect is not native to him and even when he is the first and therefore only contributor to a document.


Language corrections should ideally be done separately from content changes, but we shouldn't be too religious about that. Writers who disagree with language corrections are advised to take the matter up with the person who made that correction, rather than start commit wars.



Each language will have its own problems with pronouns; the issues addressed here are those stemming from the fact that AROS is created by a collective, and those stemming from the multiple meanings of "you" in English and its equivalents in other languages.

  • "I" is the 9th letter of the alphabet. As a pronoun it can't be used in a document, as that would be the document itself speaking. The writers of each document are supposed to be the AROS Team, and they, as a collective can't refer to themselves as "I". There are a few exceptions to this, like a draft a or a commentary, as the assumption there is that the writer himself addresses the reader. Note, however, that after a draft has been revised a few times by other contributors, this quickly becomes impractical.

  • "You" is the reader, when the reader is supposed to follow steps. In other contexts it's usually unnecessary to address the reader directly. Especially try to avoid inventing facts about "you", as in: "You as a tester won't know this implementation detail:". The same message can usually written without excluding part of the audience: "If you're a tester, you might not know this implementation detail:" or simply "This is an implementation detail testers might not know:".

  • "We" is the "AROS (Development/Documentation/Testing) Team", as appropriate. It does not refer to "You and I" (see "I" and "You", above). Writers who like to take the reader by the hand will find that this can also be done in ways that are less confusing, and easier on the reader.

  • "He" is the user/reader etc., referred to in the third person. We can jump high and low, but our users and readers are most likely male, and it's a simple choice to just accept that as our single third person reference, rather than having to take care to use "she", "(s)he", "they" in the singular, "she/he", etc. consistently.

    Often, there's no reason to use a pronoun at all, but don't artificially write about "the user" five times in a row.

  • "It" can be many things. (Well, one thing at a time.) This makes it easy to use for avoiding reusing the same term over and over, but do take care that the reference is a clear one. "I laid my hat next to the cushion and sat down on it" is not the kind of structure you would like use while trying to explain some intricate AROS detail. The same holds for "this", "that", "these", "there", and a few more words of a similar nature, that all may or may not refer to what you intended to write about.

Pick a different style instead of "he".


Don't use jargon abbreviations like "abbrevs", "apps", "dirs", "docs", and "params" unless they happen to be names of directories or similar. For now, we'll assume our documents will only exist in digital form, hence writing out a few words more is not going to bloat the book on your desk. Using common abbreviations from the field you're treating is o.k., but do write them out in parentheses the first time you use them. Using common abbreviations from the language in general is acceptable, if you do remember that they tend to use dots: e.g., i.e., etc., and a few more like them. Try to avoid using those at the end of the sentence, as the skipping of the full stop in those cases tends can be confusing.


If you use a term which you expect to be unknown to a considerable part of the readers, give a short description as part of the introduction. If possible, link to a page that treats the subject in more detail, and if not, remember there's always the glossary. At least:


There are quite a few terms in this project that either have specific meanings in their field or are Amiga- or AROS-specific. It would be a good thing to build a glossary for such words, giving short explanations and, where possible, linking to pages where more information can be found.

File system

Names in the AROS-DOS file system are case-insensitive. This allows the user to write them with any capitalisation he chooses. That doesn't mean, however, that we ourselves can take that freedom and write "DEVS:", "Devs:", "devs:" and maybe even "dEvS:" as we see fit. We should stick to a single pattern as well as we can.

These are names, of files, directories and devices, and they should get a leading capital; current practice appears to be that each word gets such a leading capital, if necessary ignoring that spaces have been omitted from the name. However, if part of the name is text that would normally be written entirely in capitals, then it's written that way in these cases as well. E.g. "Assign", "Libs:", "AddDataTypes", but "AROSMonDrvs".

In a number of cases, however, the case is fixed, probably because the names are passed though case-sensitive Exec. These cases should be documented, together with their general patterns and exceptions to those.

This would also mean "Env:" and "EnvArc:", although here custom seems to be to write "ENV:" and "ENVARC:". Is this acceptable, or do we need an exception? And should we need one, what would be its scope?


Some names and abbreviations are so familiar to us that we sometimes forget that they are not ordinary words. Other words apparently seem so special that we create abbreviations or capitalisations. As the mixed spelling this causes is rather confusing for the reader, we should try to limit ourselves to writing such words in only one way. An exception are the occurrences in filenames etc., where other conventions govern the way names are written.

Try to write the following words written out like this and/or using this capitalisation:

  • AROS (rather than "a.r.o.s" or "Aros"), AROS' (for "of AROS"), but (the name of the website);
  • Amiga, Amigas, AmigaOS (rather than "AOS", except for that project);
  • hard disk, floppy disk, floppy drive (rather than "HD", "HDD", "FD", "FDD");
  • PowerPC (rather than "PPC");
  • CLI;
  • Multics, Unix, Linux, POSIX (the latter being the only acronym);
  • Alt, Shift, Caps Lock, Ctrl, Delete, Backspace, Page Up, Page Down, Home, End, Insert, Enter (numeric keypad), Return (main keypad); or Alt key, Shift key, etc. to indicate it's a key.
  • Select different representations in cases where there's a good reason to do so.
  • Require "key" for the name of a key, except in combinations.


Language being rather organic, the way compounds are written can rarely be described with fixed rules. The Amiga User's Guide - AmigaDOS (1992), uses "file system", but "filename". Though we may be able to use sources like that to determine whether a space or hyphen should be used or not, and whether the word should have one or more capitals, the only way to do so consistently would be to create a compounds list, adding to it as we determine the way these should be written.

Text style

In some cases, it's necessary to pay special attention to the exact way to represent text, to avoid possible confusion.

End of quote

In cases where the contents of a quote have to be copied verbatim, counter to English usage do not include trailing punctuation (full stops, question marks, etc.) inside the quotes, but let them trail behind:

Type in the shell "MakeDir Ram:Test".

In other cases, the convention does apply. Likewise, other languages should follow the conventions for quoting in those languages, except where they would cause problems with the purpose of the quotes.

Be consistent and never include trailing punctuation, yet suffer the scorn of the language buffs.

Object names

Object names, be they function names, method names, etc., are used throughout the documentation. Some of those names start with a lower-case letter or with punctuation, which is rather confusing at the start of the sentence, as only upper-case letters are expected there. In such cases, and wherever it's unclear what type of object you're talking about, add the type in front of it: "The macro __small__ ...".


By using ReST to represent our texts, we give ourselves plenty of rope regarding sections and headings. This is also plenty of rope to hang ourselves. Some constraints on the amount and type of headings, and the characters they are indicated with, would be a good thing.

Table of content

ReST allows gathering the headings of a document in a table of content. For a document of non-trivial length such a table should be added, near the top of the document. In the location where you would want the table of content to appear, add a line with the ReST directive ".. Contents::". Normally, no title is specified for the table: this guarantees the default title for tables of content, together with its translation into each language, is used throughout the documentation.

Number of heading types

A page should not need more than four types of headings: One for the page title, and three for main sections, sections and subsections. More levels of sectioning usually means the document is too specific in the parts where extra sectioning is used; try to split off the details to a details page. If there is a really good reason to use more levels, at least limit the depth of the table of contents, so it won't jump all over the place. This is done by adding " :depth: 3" on the line below the contents directive. This can also be used, with a lower depth, when a document includes a large number of small subsections, e.g. a library documentation, including for each function the same group of documentation fields.

Page title

  • The page title is typically indicated with over- and underscored text.
  • The type of heading used for the page title is not repeated in the text. If you feel you should, you're likely trying to fit two topics into one page.
  • If a document is a chapter of a larger document, the titles of document and chapter are concatenated with a " -- " to form the page title. Don't repeat the chapter title as a separate heading.
  • A heading that is the first in the document and the only one of its type, with all other headings hierarchically below it, most likely should be (part of) the page title.
  • Page titles are written with the start of each word capitalised. This is possible because they will not include the source code names, but rather the descriptive names: Not "exec.library" but "The Exec Library".
Should combined "work -- chapter" page titles be required, so we force ourselves to think in larger units than single files? Can we stop at two levels?


  • Though ReST allows quite a bit of variation in underscoring a section heading, don't use actual underscore characters. Since they appear at the very bottom of the line, they give the impression that the text above them is just free-standing text. (That underscore character is intended for over-striking, where the underscore is added on the same line as the original text.)
  • ReST allows any length of underscoring and overscoring, provided they are at least as long as the text. This could be used to create page-wide separators, but this the focus away from their actual purpose: Stressing the heading itself. It's preferable to have lines that are not much longer than the heading.
  • Don't just note that one character is not suitable, but select fixed characters for the each depth of heading.
  • Always exactly match the length of the headings.


Headings, other than page titles, get letters in upper-case like a sentence would. Taking care of hierarchical style differences is the domain of the generation scripts; it's not done by writing a heading completely in capitals.

Trailing punctuation

Headings are a form of title. As with all titles, they do not end in punctuation other than question or exclamation marks, and then only when there is a very good reason for them.


Separators without text, transitions, have less indication of their function than headings. It's therefore preferable to give them the same look throughout the text.

  • Always use the "-" as the repeated character, unless there's a need to distinguish between different types of transition.
  • Skip a single line on each side of the punctuation line.
Select a different character for transitions.

Section terms

To allow referring to text further away than in the next or previous paragraph, we need terms for the different types of heading with the content following them. Such names may also create a bit more uniformity in the amount of information included in such a section. Where several file combine into a larger document, these files too will need such a term, and that larger document may group files together into even larger units.

Which terms to select for what.

Document structure

A clear representation of the text has no direct influence on the resulting page, but it should improve readability for those working on the documentation.


  • Try to keep your lines short. Insert line breaks; they will not cause any problems in the pages, but in the text they keep the width manageable.
  • The end of the line is a newline character, no carriage return character is involved. If the OS you document on disagrees, take care to set line-endings separately, or convert documents before committing them to the repository.
  • Limit lines to 80 characters. Considering that the final character will be a newline, that will be 79 printable characters. No need to be religious about it, but if your lines are at a slightly different length, don't make a fuss if someone does reformat them to the standard length.
  • If your headings don't fit into 80 characters, give some thought to shorter headings; they are meant to be short indicators of content, after all.
  • It doesn't make sense to use hyphens to fill a line with half a word, as on the page the text will reflow, likely leaving us with a hyphened word in the middle of a line.
The width of a line could be 81 characters in length, with 80 printable characters. On the other hand, some prefer a narrower style, like 72 characters, e.g. because they are more likely to pass through the forum without reformatting.
What if code is included, which might be wider than 80 characters? What if the code is less than 80 characters, but indenting it would make it cross the boundary?

Vertical spacing

In the text, skipping single lines is used as separation. Separating sections will therefore require at least two skipped lines to make the separation stand out. Below the heading, skip one line to make the heading stand out from the content below it.

Personally, I would skip two line for smallest section type, and one more for each larger type. With just one type of section, that would mean two lines skipped between them; with three types of section it would mean skipping four lines for main sections, three lines for normal sections and two lines for subsections.
Use a high character for the subsection underscore, say ^^^^, with the space within that character functioning as the separation from the following text instead of a skipped line, thus using a smaller separation for a less important section-type.

End of document

Allow the text some space; put a newline character at the end of the document, so there will be one empty line at the end in most readers. This give paragraphs a consistent look, always ending in an empty line.

  • Use as few characters as possible; as soon as the text stops, so does the file.
  • Use two or more blank lines; indicating the end of the section. For example, one could add one more line than between main sections, to indicate all sections ended. This also creates a bit of a bottom margin similar to the end of a paper page, but some might not like that.



Autodocs have some style issues that are particular to those documents, which are described in documentation/developers/documenting.en. Apart from those, their style should follow this style guide.


As autodocs support just a single language, the current assumptions are that all source code contributed to AROS is in English, and that all developers have a reading skill in English. This suffices for system development. A complete AROS documentation, on the other hand, would include documentation written in each supported language.

How to get from autodocs to multilingual documentation. E.g. the C-commands obviously will have to be documented in such a way. How can we structure that so all such documents get created, and that a change in an autodoc really does end up in all language versions?


Normally, all documents are translated from English, with the consequence that this section is rather small, here. For other languages it's likely to contain more guidelines on e.g. deciding whether a term should be translated or borrowed.

Would it be advisable to always list the source of a translation, as part of the page header, including the last revision of the original incorporated in the translation?


Steps to take after publication of this document, not necessarily in this order:

  • Discuss the indicated open issues (and probably some not indicated);
  • Choose between the alternatives, where indicated or following from the discussions;
  • Adapt the document accordingly;
  • Sanction the document in some way;
  • Find a place for the document, and its offspring, in the document tree;
  • Start a Glossary;
  • Start a Word list, containing words that for various reasons mentioned in this document need a documented preferred way to write them;
  • Create different-language versions of this document, translations edited for language-specific issues, with those versions going through these same steps for their language communities. Some of those communities will be bigger than others, though.

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