The symbols \prec, \succ, and their "or equals" equivalents \preccurlyeq, \succcurlyeq, \preceq, \succeq, (U+227A, U+227B, U+227C, U+227D, U+2AAF, U+2AB0) seem to be missing.
(Other variants on the \prec and \succ symbols at U+227E ... U+2281, U+22DE ... U+22E1, U+22E8, U+22E9, U+2AB1 ... U+2ABC are also missing, but are probably less commonly used.)
The symbols \prec, \succ, and their "or equals" equivalents \preccurlyeq, \succcurlyeq, \preceq, \succeq, (U+227A, U+227B, U+227C, U+227D, U+2AAF, U+2AB0) seem to be missing.
(Other variants on the \prec and \succ symbols at U+227E ... U+2281, U+22DE ... U+22E1, U+22E8, U+22E9, U+2AB1 ... U+2ABC are also missing, but are probably less commonly used.)