objective-c - In IDA Pro what is '::lower16::' in the 2nd ARM operand do?

Question

E.G I have this:

MOVW R1, #(:lower16:(selRef_stringWithUTF8String_ - 0xbeee)
MOV  R6, R0
MOVT.W R1, #(:upper16:(selRef_stringWithUTF8String_ - 0xbeee)

There is :lower16: and :upper16: before the address of the operand. I presume its because its in thumb mode and the size of the pointer to the string is too large so its fetching lower and upper portions? Please advise.