I'm of two minds about this. The problem is that the content of
<idno> is *not* defined as a URI. Thus, the "normal" way I would
suggest this be done:
<prefixDef ident="isn" matchPattern="(.*)" replacementPattern="http://isni.org/isni/$1"/>
<!-- ... -->
is a bit weird, because <prefixDef> is for URIs, not textual
content. But here the content of <idno> does happen to be a URI.
But it's not as though there is some generic TEI software you can
install which will process <prefixDef> for all your URIs which would
fail to work on an <idno>. (Not because it would not fail to work on
an <idno>, but because there is no such software. If I were to write
it someday, in which case I would probably provide a switch for
processing <idno>s or not.)
So in truth, Kevin's suggestion is probably safer.
P.S. Note that the prefix ("isn:") has to be lower case. (I forget
which RFC recommends lower case, but <prefixDef> requires it.)
> I recommend replacing:
> with this:
> which follows the URI syntax prescribed at
> http://www.isni.org/how-isni-works .