I'm trying to assign some desktop files a wide range of mime types. In this case it would be useful if PCManFM would support wildcards for example "text/*=SciTE.desktop;" and "*=burn.desktop".
You seem to have CSS turned off.
Please don't fill out this field.
There is nothing in XDG specification that says it is possible to have wildcards. See the specification at http://www.freedesktop.org/wiki/Specifications/mime-actions-spec/ page. Therefore there is no way to have those wildcards in the mimeapps.list file. I'm sorry.
Some time ago I have made a report on the freedesktop.org bugtracker to get this changed in the XDG specifications: https://bugs.freedesktop.org/show_bug.cgi?id=68090
Maybe they will really change this at some point in the future.