Intel 64 and IA-32 Architectures Software Developers Manual Volume 2A, Instruction Set Reference, A-M

3-494 Vol. 2
INSTRUCTION SET REFERENCE, A-M
If the stack segment selector RPL is not equal to the RPL of the
return code segment selector.
#SS(0) If an attempt to pop a value off the stack violates the SS limit.
If an attempt to pop a value off the stack causes a non-canonical
address to be referenced.
#NP(selector) If the return code or stack segment is not present.
#PF(fault-code) If a page fault occurs.
#AC(0) If an unaligned memory reference occurs when the CPL is 3 and
alignment checking is enabled.