Why are new combinations of Latin letters with diacritical marks not suitable for addition to Unicode?
A. There are several reasons. First, Unicode encodes many diacritical marks, and the combinations can already be produced, as noted in the answers to some questions above. If precomposed equivalents were added, the number of multiple spellings would be increased, and decompositions would need to be defined and maintained for them, adding to the complexity of existing decomposition tables in implementations. Finally, normalization form NFC (the composed form favored for use on the Web) is frozen—no new letter combinations can be added to it. Therefore, the normalized NFC representation of any new precomposed letters would still use decomposed sequences, which can already be expressed by combining character sequences in Unicode. Nothing would be gained by adding the letter with diacritical mark as a precomposed character; on the contrary, adding such a letter would add one or more multiple spellings to be reckoned with, incrementally complicating all Unicode implementations for no net ga
