In C89, external symbols were only guaranteed to have 6 significant characters, so both "mem_copy" and "memcopy" get truncated. And in modern times, I suspect

In C89, external symbols were only guaranteed to have 6 significant characters, so both "mem_copy" and "memcopy" get truncated. And in modern times, I suspect it'd just be thematically weird to have strcpy, strcat, and safeCopyString in string.h, so old conventions still stick around.