Re: Constraints on Attvalues

John Cowan (cowan@locke.ccil.org)
Thu, 27 Aug 1998 11:30:12 -0400 (EDT)


Peter Jones scripsit:

> So for my element:
> <myelem attrib="&ent;"/>
>
> &ent; can only refer to an internally declared entity, and the literal
> in the entity value, EntValue, cannot contain
> "....&Another_ent;...."
> where &Another_ent; is an external general entity.

You are quite right, provided you keep firmly in mind the distinction
between *being* an internal or external entity, and being
internally or externally *declared*.

Internal entities are those whose replacement text appears in the
declaration, and external entities are those whose replacement text
is referenced by a URI or Publicid. Either kind can be declared
either internally (in the internal subset) or externally (in the
external subset or in an external parameter entity).

It's the first property (*being* an external entity) that is forbidden
in references from attribute values. External parsed entities can only
be referenced from content.

-- 
John Cowan					cowan@ccil.org
		e'osai ko sarji la lojban.