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 in markdown files:
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>, it is possible they might NOT in the future.
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 prevent pandoc(1) from generating deprecated HTML elements such as
<br />.
Please do NOT use the markdown embedded image element.
Instead of using this markdown element to embed an image:
 <=== no thank you
Use an img HTML element with 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.
Please do NOT use **---**-style lines in markdown to create horizontal
lines or to separate sections.
Unless something is inside a markdown code block, do NOT start a
line with 3 or more dashes (-s).
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">
Please NOT use HTML elements:
<strike>...</strike> <=== no thank you
Use instead:
<del>...</del>
Please do NOT use the <tt> HTML elements:
<tt>The HTML 5 obsolete tt element is obsolete</tt> <=== no thank youInstead 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`
Please do NOT start code blocks at the left-hand edge.
```
This code block <=== no thank you
is NOT indented
```
We request that you indent the code block by 4 spaces:
```
This code block
is indented 4 spaces
```
One exception is where change bars are needed, such as
those used in next/rules.md and in next/guidelines.md.
For example, next/guidelines.md uses this markdown code block:
```
main() {
| void please_do_not_submit_this() {
| printf("The machine that goes BING!\n");
}
| please_do_not_submit_this();
}
```
Please do NOT use a trailing slash on void HTML elements.
See also this note on trailing slashes in void-element start tags.
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.
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.
Please do NOT place text on the next line after a markdown code block. Instead, place a blank line after the end of a markdown code block as this makes it easier to detect when markdown code blocks are NOT properly indented.
Instead of:
```
int
main(int foo)
{
return foo;
}
```
C compilers cannot be given a -Wno-main-arg-errors flag. <=== no thank you
Use:
```
int
main(int foo)
{
return foo;
}
```
C compilers cannot be given a -Wno-main-arg-errors flag.
BTW: note the blank line after the code block.
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)