Twitter cards work by using <meta> tags with names that include a colon: twitter:card, twitter:site, twitter:creator, etc.

The current parsing of ikiwiki's directive doesn't support using colons in names.

This patch fixes it.

Disclaimer: I don't know anything about Perl or the internals of ikiwiki but I managed to "make it work". It might still be flawed in many ways.

Twitter is not really picky about HTML and actually parses <meta> tags outside of the <head> section, so there's currently a workaround.

That's what I did on the donation page of Tails for now.