My old SCPL has 'Permanently Valid' stamped on the validity page. My old Second Class ATPL has a giant 'OBSOLETE' stamped right across the front page. There is a message there somewhere.
In regard to 'SOL' I too needed my grand daughter to translate.
Senior Pilot; "Excuse me old chap, would you be so kind to explain to me the meaning of the acronym SOL?" "Thanks awfully".
Young First Officer; "LOL. LOL, WTF, WTF, SOL, BRO".
I think I had better get one of those carrot top hair-cuts. Starting to feel old.