Letter Writing Etiquette

Faithfully - I remember it as you can't have two S's together in one letter!

Dear sir.... yours faithfully

dear mr x.... yours sincerely

WEES

I remember it by thinking if you don't have a named person i.e. it's addressed to Sir/Madam then you have faith that it will get to the right person.

Thanks everyone

That has reminded me, I have a colleague who addresses all the emails he sends to a certain group distribution as "Dear Sir/Ma'am/Other". I'm still trying to figure out who doesn't fit into either of the first two categories. ?