Change Unicode characters for alternative coloured TICK & check marks.

Remove `Tips for vim` users - do you provide the Emacs equivalent, or
Nano, Joe, etc. - how to use an editor is not our job.
This commit is contained in:
Anthony Howe committed 2025-11-24 04:08:58 -05:00
1 parent 2846b12a4a
commit 73add7628f
1 file changed
+150 -185
+150 -185
View File
@@ -1,133 +1,132 @@
<div id="markdown_guidelines"></div>
# IOCCC 29th Markdown Guidelines # IOCCC 29th Markdown Guidelines
<div id="markdown_version"></div>
## Markdown Guidelines Version ## Markdown Guidelines Version
These [Markdown Guidelines](markdown.html) are version **28.4 2025-04-28**. These [Markdown Guidelines](markdown.html) are version **28.4 2025-04-28**.
<div id="introduction"></div> <div id="introduction"></div>
## Markdown Guidelines Introduction
The IOCCC makes extensive use of [markdown](https://daringfireball.net/projects/markdown/). ## Introduction
For example, when submitting to the IOCCC we have people submit remarks
about their entry in markdown format. Every [winning entry](years.html)
uses a `README.md` markdown file as the basis for forming the `index.html`
web page for that entry. All HTML 5 generated pages on the
[Official IOCCC website](https://www.ioccc.org/index.html) start with some
markdown content. We no longer support older HTML standards and some of
our guidelines help integrate winning entries into the website more easily.
See the [markdown syntax](https://www.markdownguide.org/basic-syntax) guide. The IOCCC makes extensive use of [markdown](https://daringfireball.net/projects/markdown/). For example, when
See also the [CommonMark Spec](https://spec.commonmark.org/current/). See submitting to the IOCCC we have people submit remarks about their
the FAQ on "[remarks.md submission file](faq.html#remarks_md)". entry in markdown format. Every [winning entry](years.html) uses a `README.md`
markdown file as the basis for forming the `index.html` web page for
that entry. All HTML 5 generated pages on the [Official IOCCC website](https://www.ioccc.org/index.html)
start with some markdown content. We no longer support older HTML
standards and some of our guidelines help integrate winning entries into
the website more easily.
See the [markdown syntax](https://www.markdownguide.org/basic-syntax) guide. See also the [CommonMark Spec](https://spec.commonmark.org/current/).
See the FAQ on "[remarks.md submission file](faq.html#remarks_md)".
Nevertheless, the IOCCC does have certain practices that we ask authors to Nevertheless, the IOCCC does have certain practices that we ask authors to
follow. Some of these relate to use of markdown directly and others relate follow. Some of these relate to use of markdown directly and others relate
to injecting HTML into the markdown file. to injecting HTML into the markdown file.
In the sections below, examples will mark by <span style="color: red">✕</span> In the sections below, examples will mark by ❌ for the incorrect method
for the incorrect method and <span style="color: green">✔</span> for preferred and ✔️ for preferred correct one.
correct one.
<div id="sections"></div> <div id="sections"></div>
## Start `remarks.md` sections at level 3 ## Start `remarks.md` sections at level 3
If (it is not required) you do use sections in your `remarks.md` file (this does If (it is not required) you do use sections in your `remarks.md` file (this does
not apply to other markdown files), **PLEASE** start at level three up to level six: not apply to other markdown files), **PLEASE** start at level three up to level six:
```<!---markdown--> ```<!---markdown-->
✕ # Section Reserved ❌ # Section Reserved
✕ ## Section Reserved ❌ ## Section Reserved
✔ ### Section Level 3 ✔️ ### Section Level 3
✔ #### Section Level 4 ✔️ #### Section Level 4
✔ ##### Section Level 5 ✔️ ##### Section Level 5
✔ ###### Section Level 6 ✔️ ###### Section Level 6
``` ```
<div id="name"></div>
<div id="anchor-name"></div> <div id="anchor-name"></div>
## Replace `<a name="anchor_name"></a>` construct. ## Replace `<a name="anchor_name"></a>` construct.
```<!---html--> ```<!---html-->
✕ <a name="old_way">...</a> ❌ <a name="old_way">...</a>
✔ <div id="new_way">...</div> ✔️ <span id="new_way">...</span>
``` ```
<div id="links"></div> <div id="links"></div>
## Markdown links instead of `<a>...</a>` ## Markdown links instead of `<a>...</a>`
```<!---html--> ```<!---html-->
✕ This <a href="#link_target>HTML link text</a> works, but we prefer ❌ This <a href="#link_target>HTML link text</a> works, but we prefer
✔ [markdown link text](#link_target) ✔️ [markdown link text](#link_target)
``` ```
<div id="del"></div> <div id="del"></div><div id="strike"></div>
<div id="strike"></div>
## Replace `<strike>` or `<s>` ## Replace `<strike>` or `<s>`
```<!---html--> ```<!---html-->
✕ <strike>striked through text</strike> ❌ <strike>striked through text</strike>
✕ <s>HTML 5 striked through text</s> ❌ <s>HTML 5 striked through text</s>
✔ <del>HTML 5 striked through text</del> ✔️ <del>HTML 5 striked through text</del>
✔ ~~markdown striked through text~~ ✔️ ~~markdown striked through text~~
``` ```
<div id="ins"></div> <div id="ins"></div><div id="underline"></div>
<div id="underline"></div>
## Replace `<u>` ## Replace `<u>`
```<!---html--> ```<!---html-->
✕ <u>old tags</u> ❌ <u>old tags</u>
✔ <ins>HTML 5 tags</ins> ✔️ <ins>HTML 5 tags</ins>
``` ```
<div id="tt"></div> <div id="tt"></div>
<div id="span"></div>
## Replace `<tt>` ## Replace `<tt>`
```<!---html--> ```<!---html-->
✕ <tt>obsolete HTML</tt> ❌ <tt>obsolete HTML</tt>
✔ <span style="font-family: monospace;">monospace font</span> ✔️ <span style="font-family: monospace;">monospace font</span>
✔ `markdown style monospace` ✔️ `markdown style monospace`
``` ```
<div id="indented"></div> <div id="indent"></div>
<div id="unindented"></div>
## Always indent code blocks 4 spaces, not tab. ## Indent code blocks by four spaces, not by TAB.
```<!---sh--> ```<!---sh-->
✕ echo "This code block is NOT indented" ❌ echo "This code block is NOT indented"
``` ```
We request that you indent the code block by multiples of four (4) We request that you indent the code block by multiples of four (4)
ASCII SPACES, never TAB (␉): ASCII SPACES, never TAB (␉):
````<!---sh--> ````<!---sh-->
✔ echo "This code block is indented by multiples of 4 spaces" ✔️ echo "This code block is indented by multiples of 4 spaces"
✔ # The top level starts with a 4 ASCII space indent. ✔️ # The top level starts with a 4 ASCII space indent.
✔ # ✔️ #
✔ # Only indent with multiples of 4 ASCII spaces. ✔️ # Only indent with multiples of 4 ASCII spaces.
✔ # 2nd level indent needs 8 ASCII spaces (no tabs). ✔️ # 2nd level indent needs 8 ASCII spaces (no tabs).
✔ # 3rd level indent needs 12 ASCII spaces (no tabs). ✔️ # 3rd level indent needs 12 ASCII spaces (no tabs).
✔ # etc. ✔️ # etc.
```` ````
Alternatively its possible to use ` ``` ` marks, without the initial Alternatively its possible to use ` ``` ` marks, without the initial
four (4) space indentation. This is usually the better method. four (4) space indentation. This is usually the better method.
````<!---markdown--> ````<!---markdown-->
✔ ``` ✔️ ```
✔ The same thing applies to any markdown block bracketed by ``` lines. ✔️ The same thing applies to any markdown block bracketed by ``` lines.
✔ ``` ✔️ ```
```` ````
<div id="tabs"></div> <div id="tabs"></div><div id="spaces"></div>
<div id="spaces"></div>
## Do not use ASCII TAB in markdown files. ## Do not use TAB in markdown files.
Please do **NOT** indent with ASCII TABs (␉), **OR** use any ASCII TAB Please do **NOT** indent with ASCII TABs (␉), **OR** use any ASCII TAB
(␉) anywhere inside a markdown file. (␉) anywhere inside a markdown file.
@@ -136,16 +135,16 @@ While we have nothing against the ASCII TAB (␉) character in general,
we have discovered that ASCII TAB (␉) characters create problems when we have discovered that ASCII TAB (␉) characters create problems when
used as part of the leading whitespace within a markdown file. used as part of the leading whitespace within a markdown file.
If you need to indent two (2 or more levels, use multiples of four (4) If you need to indent two (2) or more levels, use multiples of four (4)
ASCII SPACES. ASCII SPACES.
````<!---markdown--> ````<!---markdown-->
``` ```
✕ ␉Please do **NOT**␉use ASCII tabs␉in markdown files. ❌ ␉Please do **NOT**␉use ASCII tabs␉in markdown files.
✕ ␉␉Please do **NOT** indent markdown with ASCII tabs. ❌ ␉␉Please do **NOT** indent markdown with ASCII tabs.
✕ ␉We don't␉mind␉tabs␉in␉general, ❌ ␉We don't␉mind␉tabs␉in␉general,
✕ ␉We just ask that you NOT use them in markdown files. ❌ ␉We just ask that you NOT use them in markdown files.
``` ```
```` ````
@@ -153,70 +152,37 @@ And to clarify, we are only talking about markdown files, not C code or
any other non-markdown content: any other non-markdown content:
````<!---c--> ````<!---c-->
✔ printf("It is fine to use tabs in Obfuscated C code.\n"); ✔️ printf("It is fine␉to␉use tabs in Obfuscated C code.\n");
✔ /* if you wish */ ✔️ /*␉if␉you␉wish */
✔ // We ask that you to NOT use ASCII tab characters in your remarks.md writeup, ✔️ // We ask that you to NOT use ASCII tab characters in your remarks.md writeup,
✔ // or in any other markdown files within your entry, please. ✔️ // or in any other markdown files within your entry, please.
```` ````
**NOTE**: Again, you are **perfectly welcome** to use ASCII tab **NOTE**: Again, you are **perfectly welcome** to use ASCII tab characters
characters in your C code and other non-markdown files. We simply ask in your C code and other non-markdown files. We simply ask that
that you do **NOT** use any ASCII TAB (␉) characters in markdown files. you do **NOT** use any ASCII TAB (␉) characters in markdown files.
<div id="vim-tabs"></div> <div id="code"></div><div id="languages"></div>
### Tip for `vim` users
If you use `vim` you can put in your `.vimrc` file (usually `~/.vimrc`)
the following settings to make sure the tabs are not put in without you
noticing:
```<!---vim-->
set tabstop=8 " a tab is 8 spaces (or whatever you wish it to be set to)
set softtabstop=4 " ...but when inserting/backspacing use 4 spaces
set shiftwidth=4 " ...and auto-indent 4 spaces (when autoindent is set)
set expandtab " ...expand tab into spaces
```
If you have file type detection enabled you can, if you prefer, have
these settings set just for markdown files:
```<!---vim-->
autocmd! Filetype markdown setlocal set tabstop=8 softtabstop=4 shiftwidth=4 expandtab
```
This will prevent the tab key from inserting tabs; rather it will insert
four (4) spaces.
To **VERIFY** that there are no tabs in a file you may do, in command
mode:
```
/\t
```
If you're in insert mode hit `ESC` first.
<div id="code"></div>
<div id="languages"></div>
## Use HTML comments for code block language syntax. ## Use HTML comments for code block language syntax.
We request that [fenced markdown code blocks](https://www.markdownguide.org/extended-syntax/#fenced-code-blocks) We request that [fenced markdown code blocks](https://www.markdownguide.org/extended-syntax/#fenced-code-blocks)
**NOT** specify a language directly. **NOT** specify a language directly.
````<!---markdown--> ````<!---markdown-->
✕ ```c ❌ ```c
✕ int main(void) {return 0;} ❌ int main(void) {return 0;}
✕ ``` ❌ ```
```` ````
Instead, put the language inside an HTML comment, separated from the Instead, put the language inside an HTML comment, separated from the
markdown code block starting fence by a space: markdown code block starting fence by a space:
````<!---markdown--> ````<!---markdown-->
✔ ```<!---c--> ✔️ ```<!---c-->
✔ int main(void) {return 0;} ✔️ int main(void) {return 0;}
✔ ``` ✔️ ```
```` ````
**IMPORTANT**: The **initial** &nbsp; **\` \` \`** &nbsp; must be **IMPORTANT**: The **initial** &nbsp; **\` \` \`** &nbsp; must be
@@ -225,9 +191,8 @@ followed by an **ASCII SPACE**, and **THEN** an **opening** **
the **language** and **FINALLY** a **closing** "`-->`" (two "`-`"s the **language** and **FINALLY** a **closing** "`-->`" (two "`-`"s
followed by a "`>`"). followed by a "`>`").
<div id="text"></div>
<div id="code-text"></div>
<div id="code-and-text"></div> <div id="code-and-text"></div>
## Ensure blank line between code block and text. ## Ensure blank line between code block and text.
Please do **NOT** place text on the next line after a markdown code Please do **NOT** place text on the next line after a markdown code
@@ -236,28 +201,28 @@ block as this makes it easier to detect when markdown code blocks are
**NOT** properly indented. **NOT** properly indented.
````<!---markdown--> ````<!---markdown-->
✕ ``` ```
✕ int int
✕ main(int foo) main(int foo)
✕ { {
✕ return foo; return foo;
✕ } }
✕ ``` ❌ ```
✕ C compilers cannot be given a -Wno-main-arg-errors flag. ❌ C compilers cannot be given a -Wno-main-arg-errors flag.
✔ ``` ```
✔ int int
✔ main(int foo) main(int foo)
✔ { {
✔ return foo; return foo;
✔ } }
✔ ``` ✔️ ```
✔ ✔️
✔ C compilers cannot be given a -Wno-main-arg-errors flag. ✔️ C compilers cannot be given a -Wno-main-arg-errors flag.
```` ````
<div id="void"></div> <div id="tag-slash"></div>
<div id="slash"></div>
## Do not add trailing slash to void HTML tags. ## Do not add trailing slash to void HTML tags.
Please do **NOT** use a trailing slash on Please do **NOT** use a trailing slash on
@@ -269,61 +234,59 @@ The trailing slash on void HTML elements has no effect and interacts
badly with unquoted attribute values. badly with unquoted attribute values.
```<!---html--> ```<!---html-->
✕ <br/> ❌ <br/>
✕ <hr/> ❌ <hr/>
✕ <img src="1984-anonymous-tattoo.jpg" ❌ <img src="1984-anonymous-tattoo.jpg" alt="image of a tattoo of
alt="image of a tattoo of the 1984 anonymous C code" the 1984 anonymous C code" width=600 height=401 />
width=600 height=401 />
✔ <br> ✔️ <br>
✔ <hr> ✔️ <hr>
✔ <img src="1984-anonymous-tattoo.jpg" ✔️ <img src="1984-anonymous-tattoo.jpg" alt="image of a tattoo of
alt="image of a tattoo of the 1984 anonymous C code" the 1984 anonymous C code" width=600 height=401>
width=600 height=401>
``` ```
<div id="br"></div> <div id="br"></div><div id="backslash"></div>
<div id="backslash"></div>
## Do not use a trailing backslash (`\`) outside of a code block ## Do not use a trailing backslash outside of a code block
Unless the line is inside a markdown code block, please do **NOT** end Unless the line is inside a markdown code block, please do **NOT** end
a markdown line with a trailing backslash (`\`). Instead use a trailing a markdown line with a trailing backslash (`\`). Instead use a trailing
`<br>`. `<br>`.
```<!---markdown--> ```<!---markdown-->
✕ In markdown,\ ❌ In markdown,\
✕ do NOT use trailing\ ❌ do NOT use trailing\
✕ backslashes outside of\ ❌ backslashes outside of\
✕ a code block ❌ a code block
✔ In markdown,<br> ✔️ In markdown,<br>
✔ use trailing<br> ✔️ use trailing<br>
✔ br's outside of<br> ✔️ br's outside of<br>
✔ a code block ✔️ a code block
✔ ``` ✔️ ```
✔ This is OK\ ✔️ This is OK\
✔ inside a\ ✔️ inside a\
✔ markdown code\ ✔️ markdown code\
✔ block ✔️ block
✔ ``` ✔️ ```
✔ `This is OK\` ✔️ `This is OK\`
```` ````
Doing it this way will prevent `pandoc(1)` from generating deprecated Doing it this way will prevent `pandoc(1)` from generating deprecated
HTML elements such as `<br />`. HTML elements such as `<br />`.
<div id="img"></div> <div id="img"></div>
<div id="images"></div>
## Do not use markdown style images ## Do not use markdown style images
Instead of using this markdown element to embed an image: Instead of using this markdown element to embed an image:
```<!---markdown--> ```<!---markdown-->
✕ ![alt text](filename.png "Title") ❌ ![alt text](filename.png "Title")
✔ <img src="filename.png" ✔️ <img src="filename.png"
alt="describe the filename.png image for someone who cannot view it" alt="describe the filename.png image for someone who cannot view it"
width=PIXEL_WIDTH height=PIXEL_HEIGHT> width=PIXEL_WIDTH height=PIXEL_HEIGHT>
@@ -336,9 +299,8 @@ and `height` information so browsers have to slow down on rendering
text around the image until it can internally determine the image size. text around the image until it can internally determine the image size.
<div id="hr"></div> <div id="hr"></div>
<div id="lines"></div>
<div id="horizontal"></div> ## Replace markdown style horizontal lines.
## Please do NOT use markdown style horizontal lines
Please do **NOT** use `---` style lines in markdown to create horizontal Please do **NOT** use `---` style lines in markdown to create horizontal
lines or to separate sections. lines or to separate sections.
@@ -353,43 +315,46 @@ values.
If a horizontal line is really needed, use: If a horizontal line is really needed, use:
```<!---html--> ```<!---html-->
✕ * * * ❌ * * *
✕ - - - ❌ - - -
✕ --- ❌ ---
Regular divider... Regular divider...
✔ <hr> ✔️ <hr>
A short divider... A short divider...
✔ <hr style="width:10%;text-align:left;margin-left:0"> ✔️ <hr style="width:10%;text-align:left;margin-left:0">
``` ```
<div id="parentheses"></div> <div id="parentheses"></div>
## Do not put a literal "`(`" or "`)`" in markdown link titles ## Do not put a literal "`(`" or "`)`" in markdown link titles
```<!---markdown--> ```<!---markdown-->
✕ [some (text)](https://example.com/curds) ❌ [some (text)](https://example.com/curds)
✔ [some &lpar;text&rpar;](https://example.com/curds) ✔️ [some &lpar;text&rpar;](https://example.com/curds)
✕ [ls(1)](https://example.com/ls-man-page.1) ❌ [ls(1)](https://example.com/ls-man-page.1)
✔ [ls&lpar;1&rpar;](https://example.com/ls-man-page.1) ✔️ [ls&lpar;1&rpar;](https://example.com/ls-man-page.1)
``` ```
<div id="closing-parentheses"></div> <div id="closing-parentheses"></div>
## Do not end markdown links with "`))`" ## Do not end markdown links with "`))`"
Markdown links that end in "`))`" complicate parsing and sometimes lead Markdown links that end in "`))`" complicate parsing and sometimes lead
to incorrect URLs or file paths. to incorrect URLs or file paths.
```<!---markdown--> ```<!---markdown-->
✕ [some text](https://example.com/foo_(bar)) ❌ [some text](https://example.com/foo_(bar))
✔ [some text](https://example.com/foo_&lpar;bar&rpar;) ✔️ [some text](https://example.com/foo_&lpar;bar&rpar;)
✕ This thing, ([some text](some/path)), is NOT ideal. ❌ This thing, ([some text](some/path)), is NOT ideal.
✔ This thing, [some text](some/path), is better. ✔️ This thing, [some text](some/path), is better.
``` ```
<div id="italics"></div> <div id="italics"></div>
## Use `_` for italics in markdown ## Use `_` for italics in markdown
Please do **NOT** use `*` (single asterisk) for italics in markdown. Please do **NOT** use `*` (single asterisk) for italics in markdown.
@@ -398,12 +363,12 @@ parsing and sometimes lead to incorrect results. This can especially
go for when it is **_bold and italic_**. go for when it is **_bold and italic_**.
```<!---markdown--> ```<!---markdown-->
✕ *this text is italic* ❌ *this text is italic*
✔ _this text is italic_ ✔️ _this text is italic_
✕ ***this text is bold italic*** ❌ ***this text is bold italic***
✔ **_this text is bold italic_** ✔️ **_this text is bold italic_**
✔ _**this text is bold italic**_ ✔️ _**this text is bold italic**_
``` ```
**BTW**: the astute reader might notice that some cases of `*` for **BTW**: the astute reader might notice that some cases of `*` for
italic might have slipped through. We do ask you, however, to please italic might have slipped through. We do ask you, however, to please