- gmi:header? objprocedure
- gmi:header level titleprocedure
- gmi:header:level headerprocedure
- gmi:header:text headerprocedure
level is a fixnum and title a string.
For a header created by gmi:read, if *strict-gemtext-headers* is truthy (the default), then (<= 1 level 3); otherwise (<= 1 level).