6.9 KiB
IOCCC markdown best practices
The IOCCC makes extensive use of markdown.
For example, we submitting to the IOCCC, we have people
to submit remarks about entry in markdown format. Every
winning IOCCC entry uses a README.md markdown file
as the basis for forming the index.html web page for that entry.
All generated HTML pages on the Official IOCCC web site
start with some markdown content.
See the markdown syntax guide. See also CommonMark Spec.
Nevertheless, the IOCCC does have certain practices that we ask authors to follow. Some these relate to use of markdown directly, others relate to injecting HTML into the markdown file.
In particular there are things we ask people to please do NOT use markdown files:
Do not use name attributes in HTML a tags
Please do not use the HTML construct:
<a name="string">\</a> <=== no thank you
as those are NOT part of the HTML 5 standard.
Instead use:
<div id="string">...\</div>
where the "..." is the HTML you want to "name". The div encapsulates the HTML you want to name: I.e., the target of some "<a href="#string">" or some other "<a href="URL#string">" for the given page URL.
There are certain HTML Elements that cannot have internal "<div id="string">...</div>". For example you cannot do this:
# <div id="string">This will not work</div>
For things like headings, you have to surround them as in:
<div id="string">
# This will work
</div>
While some browsers will still recognize the HTML construct "<a name="string"></a>", they may not in the future.
Do not use trailing backslash outside of a code block
Unless the line is inside a markdown code block, please do NOT end a markdown line with a trailing backslash ("\"). Instead use a trailing "<br>".
Instead of:
In markdown,\ <=== no thank you
do not use trailing\
backslashes outside of\
a code block
use:
In markdown,<br>
use trailing<br>
br's outside of<br>
a code block
Again, use of a trailing backslash ("\") inside a markdown code block is fine:
```
This is OK\
inside a\
markdown code\
block
```
This will avoid pandoc(1) generating deprecated HTML elements such as \<br />.
Do not use markdown image elements
Please do not use the markdown embedded image element.
Instead of using this markdown element to embed an image:
 <=== no thank you
Use a "img" HTML element with "alt", "alt", "width" and "length" attributes:
<img src="filename.png"
alt="describe the filename.png image for someone who cannot view it"
width=PIXEL_WIDTH height=PIXEL_HEIGHT>
For example, instead of:
 <=== no thank you
use this HTML:
<img src="1984-anonymous-tattoo.jpg"
alt="image of a tattoo of the 1984 anonymous C code"
width=600 height=401>
The problem goes beyond the fact that pandoc(1) generates problematic
HTML from the markdown image construct, the resulting HTML does not
have "width" and "height" information so browsers have to slow down
on rendering text around the image until it can internally determine
the image size.
Do not use markdown style horizontal lines
Please do not use "---"-style lines in markdown to create horizontal lines, nor to separate sections.
Unless something is inside a markdown code block, do not start a line with 3 or more dashes ("-").
Such causes pandoc(1) to generate "<hr />". The "<hr
/>" has no effect in standard HTML 5 and interacts badly with
unquoted attribute values.
If a horizontal line is really needed, use:
<hr>
If a short line is needed, use:
<hr style="width:10%;text-align:left;margin-left:0">
Do not use the strike HTML element
Please not use the HTML element:
<strike>...</strike> <=== no thank you
Use instead:
<del>...</del>
Do not use tt HTML elements
Please do not use the tt HTML elements:
<tt>The HTML 5 obsolete tt element is obsolete</tt> <=== no thank you
Instead use either a monospaced span:
<span style="font-family: monospace;">Use of monospaced font is one option</span>
Or better and easier still, use an inline markdown code block:
`inline markdown code block is easier and much better`
Do not use un-indented code clocks
Please do not start code blocks at the left-hand edge.
```
This code block <=== no thank you
is not indendted
```
```
We request that you indent the code block by 4 spaces:
This code block
is intented 4 spaces
## Do not add trailing slash on void HTML elements
Please do not use trailing slash on [void HTML
elements](https://github.com/validator/validator/wiki/Markup-»-Void-elements).
See also this note on [trailing slashes in void-element start
tags](https://github.com/validator/validator/wiki/Markup-»-Void-elements#trailing-slashes-in-void-element-start-tags-do-not-mark-the-start-tags-as-self-closing).
The trailing slash on void HTML elements has no effect and interacts badly with unquoted attribute values.
For example, please do not use:
```
<br/> <=== no thank you
```
Instead use just:
```
<br>
```
And for example, please do not use:
```
<hr/> <=== no thank you
```
Instead use just:
```
<hr>
```
And for example, please do not use:
```
<img src="1984-anonymous-tattoo.jpg"
alt="image of a tattoo of the 1984 anonymous C code"
width=600 height=401 /> <=== no thank you
```
Instead use just:
```
<img src="1984-anonymous-tattoo.jpg"
alt="image of a tattoo of the 1984 anonymous C code"
width=600 height=401>
```
etc.
## Do not end markdown links in ))
Please do not end a markdown links with a double closed parenthesis "))".
Markdown links that end in "))" complicate parsing and sometimes lead
to incorrect URLs or file paths.
Instead of:
```
[some text](https://example.com/foo_(bar)) <=== no thank you
```
Use:
```
[some text](https://example.com/foo_(bar))
```
Instead of:
```
This thing ([some text](some/path)) is not ideal. <=== no thank you
```
Use:
```
This thing, [some text](some/path), is better.
```
## Do not put ('s or )' markdown link titles
Please do not use parenthesis inside the markdown link titles.
Instead of:
```
[some (text)](https://example.com/cyrds) <=== no thank you
```
Use:
```
[some (text)](https://example.com/cyrds)
```
Instead of:
```
[ls(1)](https://example.com/ls-man-page.1) <=== no thank you
```
Use:
```
[ls(1)](https://example.com/ls-man-page.1)
```