Hello. I am in need of creating a tag like the IMG tag. I'm not trying to reinvent the wheel; I don't know how it was invented. Without declaring an entity explicitly in the dtd, ie

!ENTITY src SYSTEM "apic.gif" NDATA gif

How can a make it a placeholder, dependent on the xml document authors input? In other words, I need a src tag for the IMG tag, without declaring what the src is...

does that make sense?

Please help!

Thank you.