The identifier for the entry is the element name, which is appended to the end of the MMCTOCENTRY structure passed in the pmmctocentry parameter. It is not case-sensitive. If mmioCFAddEntry expands the current number of entries past the number currently allocated, when a mmioCFClose is called, the CTOC gets written following the CGRP chunk in the file. The mmioCFAddEntry function operates only on the CTOC in memory and does not do any expansion of the file itself.