[JD557]

What about text preceded by a # (eg. HTML colors, hash tags, numerals...)? Do you escape # if it's next character is not a whitespace?

[it33]

Correct, escape if # is not followed by whitespace. Mattermost markdown is based on GitLab Flavored Markdown: https://gitlab.com/gitlab-org/gitlab-ce/blob/6-4-stable/doc/...