The obliterated character needed for paleolitic studies, or to encode any texts in which the character is not recognizable already exists: isn't it the REPLACEMENT CHARACTER?
Such base character should be rendered with a spacing glyph (for example a circle filled with a grey pattern, or the rounded box with oblique hatches that we sometimes see in charts) It is not the same as the missing letter which is not there because of alteration of the source document.
I think this is a typographical decision, so perhaps a glyph issue. Personally, there is no way I'd let a rounded box with oblique hatches anywhere near any scholarly work that I was typesetting. :)
JH
Tiro Typeworks www.tiro.com Vancouver, BC [EMAIL PROTECTED]
I sometimes think that good readers are as singular,
and as awesome, as great authors themselves.
- JL Borges
