'-f markdown' vs. '-f gfm'

[jsx97]

Hello! Could someone show the practical difference between -f markdown and -f gfm? I do understand Pandoc's Markdown and GitHub Flavored Markdown are not the same thing, and therefore there is, of course, some difference between using -f markdown and -f gfm, but what is it exactly? Could you show some examples?

• pandoc -f markdown input.md -o output.htm
• pandoc -f gfm input.md -o output.htm

[jsx97]

This question is not longer relevant to me, but here is what I looked for. Markup that doesn't use Pandoc's-Markdown-specific syntax (such as ::: for fenced divs), but nevertheless converted using -f markdown and using -f gfm differently:

this is a list:
- list item 1
- list item 2

pandoc -f markdown input.md -o output1.htm:

<p>this is a list: - list item 1 - list item 2</p>

pandoc -f gfm input.md -o output2.htm:

<p>this is a list:</p>
<ul>
<li>list item 1</li>
<li>list item 2</li>
</ul>

[tarleb]

The most informative is probably to look at the difference of pandoc --list-extensions=markdown and pandoc --list-extensions=gfm.

Here's what I get when I run diff <(pandoc --list-extensions=markdown) <(pandoc --list-extensions=gfm):

1,3c1
< -abbreviations
< +all_symbols_escapable
< -angle_brackets_escapable
---
> +alerts
5,13c3,6
< +auto_identifiers
< -autolink_bare_uris
< +backtick_code_blocks
< +blank_before_blockquote
< +blank_before_header
< +bracketed_spans
< +citations
< -compact_definition_lists
< +definition_lists
---
> -attributes
> +autolink_bare_uris
> -bracketed_spans
> -definition_lists
15,21c8,10
< -emoji
< +escaped_line_breaks
< +example_lists
< +fancy_lists
< +fenced_code_attributes
< +fenced_code_blocks
< +fenced_divs
---
> +emoji
> -fancy_lists
> -fenced_divs
23,26c12
< -four_space_rule
< -gfm_auto_identifiers
< +grid_tables
< -gutenberg
---
> +gfm_auto_identifiers
28,50c14,15
< +header_attributes
< -ignore_line_breaks
< +implicit_figures
< +implicit_header_references
< +inline_code_attributes
< +inline_notes
< +intraword_underscores
< +latex_macros
< +line_blocks
< +link_attributes
< -lists_without_preceding_blankline
< -literate_haskell
< -mark
< -markdown_attribute
< +markdown_in_html_blocks
< -mmd_header_identifiers
< -mmd_link_attributes
< -mmd_title_block
< +multiline_tables
< +native_divs
< +native_spans
< -old_dashes
< +pandoc_title_block
---
> -implicit_figures
> -implicit_header_references
52c17
< +raw_attribute
---
> -raw_attribute
54d18
< +raw_tex
56,62c20,21
< -short_subsuperscripts
< +shortcut_reference_links
< +simple_tables
< +smart
< +space_in_atx_header
< -spaced_reference_links
< +startnum
---
> -smart
> -sourcepos
64,65c23,24
< +subscript
< +superscript
---
> -subscript
> -superscript
67d25
< +table_captions
69,70c27
< -tex_math_double_backslash
< -tex_math_single_backslash
---
> +tex_math_gfm