At some point in the distant past symbol tables allowed symbols up to 6 characters long. Longer names were allowed but anything beyond 6 characters were gone by

At some point in the distant past symbol tables allowed symbols up to 6 characters long. Longer names were allowed but anything beyond 6 characters were gone by the time the linker was invoked. So ThisIsAFunction() and ThisIsAnotherFunction() would resolve to ThisIs(). It would hopefully produce an error at link time.