American Airlines uses TS due to the engine size.
EVA - a Taiwanese airline uses the Airline IATA Code of BR.
Qantas Airways uses the airline code QF.
The codes that use Ts and Es can refer to codes in programming languages like TypeScript (which uses .ts extension for files) and HTML (where is often used for the title element). Each programming language has its own syntax and conventions for how Ts and Es are used.
Klm
Jet2.com has the IATA airline designator code LS
Easy jet
American airlines
KLM
A Navy Flight Surgeon uses this very insignia. Airline, I do not know.
I believe it is Transaero Airlines
Ryanair
UV is for Universal Airways.