Some notes to markdown_compare.tsv

[tylerlong]

Note 1

Glip's _underline_ is incompatible with the other 3 flavors (_italic_), which is a big disadvantage, in my opinion.

Note 2

|col1|col2|col3| is not a valid table in GFM. In GFM, table header is mandatory:

h1|h2|h3
-|-|-
c1|c2|c3

h1	h2	h3
c1	c2	c3

Note 3

GFM does support Table with quote:

> h1|h2|h3
> -|-|-
> c1|c2|c3

h1	h2	h3
c1	c2	c3

[grokify]

Those are good notes.

General Syntax Incompatibility

Over time, many organizations have created different flavors of Markdown, hence the need for the CommonMark (CM) project with representatives from Github, Stack Overflow, Reddit, etc. In a reading of CommonMark, it seems like it is incomplete since it does not support everything supported by GFM yet, e.g. tables. So standards setting appears to still be a work in progress.

Overall, it is better to align more with CM/GFM when possible.

Syntax Incompatibility (Glip underline, Slack bold/links)

• While Glip's "Glipdown" underline syntax means italic in CM and GFM, they do have an alternate syntax for italic that is supported by Glip. It seems a bit overly flexible for CM and GFM to support two forms of italic (and bold) while not supporting underline.
• Slack's bold syntax means italic for CM and GFM.
• Slack's link format uses the Skype syntax and not the Markdown syntax.

Tables

• Noted that GFM and Glip have different table notations. I may have to change the comparison reference to Markdown or HTML since those are multi-line and a TSV may not support rendering it properly.
• Slack does not support tables at all, preferring create a similar rendering with short fields. The CommonChat format supports short fields and MD table (via passthrough).