DOCBOOK: RFE 136: co in userinput

[Norman Walsh <ndw@nwalsh.com>]

We've been discussing this issue for a while. I took the action
item[1] to form a concrete proposal.

To recap, consider this example:

<screen><prompt>#</prompt> <userinput>foo <co id="foo"> \
bar <co id="bar"> \
baz <co id="baz"></userinput>
</screen>

As it stands, this isn't valid because you can't put a co inside
userinput.

What we'd really like is <co> as an inclusion on <screen> but we can't
have that.

In order to fix this in XML, we're going to have to add co to the
content model of some elements. As a consequence, the DTD will not be
able to distinguish co in userinput in screen from co in userinput in
para.

1. We could make the latter an error (not checkable by the DTD) or we
   could just allow it.

Assuming we do this, what elements need to allow co. Looking at the
content model for screen:

screen ::=

(#PCDATA|footnoteref|xref|abbrev|acronym|citation|citerefentry|
 citetitle|emphasis|firstterm|foreignphrase|glossterm|footnote|
 phrase|quote|trademark|wordasword|link|olink|ulink|action|
 application|classname|methodname|interfacename|exceptionname|
 ooclass|oointerface|ooexception|command|computeroutput|database|
 email|envar|errorcode|errorname|errortype|filename|function|
 guibutton|guiicon|guilabel|guimenu|guimenuitem|guisubmenu|
 hardware|interface|keycap|keycode|keycombo|keysym|literal|
 constant|markup|medialabel|menuchoice|mousebutton|option|
 optional|parameter|prompt|property|replaceable|returnvalue|
 sgmltag|structfield|structname|symbol|systemitem|token|type|
 userinput|varname|anchor|author|authorinitials|corpauthor|
 modespec|othercredit|productname|productnumber|revhistory|remark|
 subscript|superscript|inlinegraphic|inlinemediaobject|
 inlineequation|synopsis|cmdsynopsis|funcsynopsis|classsynopsis|
 fieldsynopsis|constructorsynopsis|destructorsynopsis|
 methodsynopsis|indexterm|beginpage|co|lineannotation)*

I suggest:

2. We add co to the content model of prompt, userinput, computeroutput,
   replaceable, and systemitem. (And nothing else.)

Comments?

                                        Be seeing you,
                                          norm

[1] http://lists.oasis-open.org/archives/docbook-tc/200105/msg00005.html
-- 
Norman Walsh <ndw@nwalsh.com>      | It is good to have an end to
http://www.oasis-open.org/docbook/ | journey toward; but it is the
Chair, DocBook Technical Committee | journey that matters, in the
                                   | end.--Ursula K. Le Guin