The syntax/relaxng/phrase.rnc file currently defines both a code.elem pattern and a code.elem.strict, with corresponding code.inner and code.inner.strict patterns for their content models. But the definitions for code.inner and code.inner.strict are actually identical (=common.inner.phrasing). And the attribute model for code.elem and code.elem.strict is also identical (=code.attrs). So code.elem and code.elem.strict are actually identical.

code.elem is actually not currently reference by any other pattern, code.elem.strict is in common.elem.phrasing. So to rationalize things, common.elem.phrasing should reference code.elem instead, and the code.*.strict stuff can just be removed.

(Based on doing some quick archaeology through the revision history, I can see that it seems like the code.*.strict stuff is the last remaining bit of cruft left over from an earlier (and more complicated) incarnation of the schema, in which the *.*.strict stuff was used in many other content models.)