There are 26 letters in the Signal flag alphabet. This post does not include the repeaters and pennants. In the pictures I put together in Paint Shop Pro I show the flag followed by the name and then next what it means.
When some of these flags are put together for 2 or 3 flag messages they have a totally different meaning. One example is the Bravo Zulu (BZ) which means “Well Done” when it is put together. Below is an example of IB Designs, USA. Link takes you directly to the BZ page.