"glyph (content) show a character by looking up reference"
Wouldn't this function need a URI for looking up the reference? Or if the content is the URI, I think the param name is a bit misleading.
(from Martin Holmes)
changed to "uri"
deal with #16, #17, #19, #20; rethinking list of headeronly elements …
…is done; fixed Schematron check of headeronly so that it works