Original Post
The Unicode 6.0 standard, section 7.9, mentions a number of blocks containing combining marks. One of these blocks, 'Combining Marks for Symbols' runs from U+20D0 to U+20FF. Now, there are a number of code points in that range which are not assigned (at least not in version 6.0). The implication seems to be that those unassigned code points are reserved for additional combining marks, in future revisions. Is there any way of deducing this implication purely from the files in the Unicode database? I'd like to avoid having to trawl the Unicode PDF document for mention of potential future code point allocations.
I see that the database labels combining characters for assigned code points with General Category values of 'Mn', 'Mc', or 'Me', but since unassigned code points aren't listed in the database it doesn't look like I can infer their intended future use. But maybe I've missed a trick somewhere?
To ask the question another way, what's a reasonably efficient way of determining if a code point is a combining mark? Should/could the algorithm include as-yet-unassigned code points in its domain?
I see that the database labels combining characters for assigned code points with General Category values of 'Mn', 'Mc', or 'Me', but since unassigned code points aren't listed in the database it doesn't look like I can infer their intended future use. But maybe I've missed a trick somewhere?
To ask the question another way, what's a reasonably efficient way of determining if a code point is a combining mark? Should/could the algorithm include as-yet-unassigned code points in its domain?
