Ah! Ok. It's not a signature. It would have to be a reasonably clearly seen separate cane - even when used as part of a complex cane setup.
The reason one of my star weights has a hard-to-see "py" cane is that it is one of the 2mm standard, separate canes that has been squashed amongst the other canes that surround it, but under a magnifyer it is easy enough to see what it is (although the dealer I bought it from did not spot it!).