Nah you have just been the unfortunate victim of my dismay : a few years ago when I started collecting/fixing old gear and looking at service manuals and datasheets and stuff, it didn't take long before I read pS instead ps somewhere. It shocked me at first, especially coming from official documents from leading TE brands... then I realized many brands did that, for a reason that still escapes me. Don't units mean anything even for engineering companies ?!
How hard can it be to use the proper unit, seconds instead of Siemens ? If anything it's more work on the keyboard to type pS rather than ps. So I don't get it.
I can sorta understand it when you want to DISPLAY "ps" on a 7segment display, because well you have technical limitations of course, so a capital S is better than nothing at all... but when printing it on paper, I don't understand....
Even more hard to understand is that a given manufacturer is not consistent and will sometimes write ps and sometimes pS. It just blows my mind. Why don't they do that with just about any and every other unit in all their TE for all of their documents ? Either you respect units or you don't, but special casing this poor unit of time is.. .well it still boggles my mind.
Maybe the grey bears on here will have some insight...
EDIT : maybe in the '50s and '60s the spelling was not standardized just yet ? Maybe the Siemens was not really being used back then and therefore nobody would feel there was any ambiguity and people would just write 's' or 'S' depending on the mood and nobody would even see anything wrong or odd about it ?! I don't know...