So I’ve been looking around in SRK for a while, and I have a question, if people post combos they use numbers for some combos.
If there is a topic already for the meaning of the two-letter-words (I think I understand them, but just in-case) and the numbers.
I can’t explain, sorry. 
More than likely, it’ll all make sense if you look at the number pad on your keyboard. But, to be thorough, check out the Wikipedia on the SRK home page.
im confused, for what system and what games are u talking about?
Are you talking about the notation for moves? See the keypad on your keyboard and imagine an arcade stick. QCFs would be 236 and the DP motion would be 623. Different notations would be used in different game communities. Dustloop comes to mind as they use numbers instead of letters for motions.