A quick way to generate random symbols in Q, with or without replacement is using the following idiom:
where x corresponds to the number of symbols in the output list and y is the number of letters for each symbol.
Interestingly, only the letters a though p are used, which gives a possible number of 16^y possible combinations.
-10?`1 / Ten random letters from a to p without replacement
10 ? `1 /Ten random letters from a to p with replacement
L: asc -256 ? `1 / `#s `aa`ab…`pp
-17?`1 / `length