Hi,

I have an array of data with various combinations of two-
letter IDs for each observation. For instance, observation
1 has the following 6 IDs "FO CH GM HO VW MI" (in that
format), observation 2 has just 1 ID "GM", observation 3
has 4 IDs "NI VW MI CH" and so forth. In theory, there is
no limit for how many IDs an observation can have, but
glancing down the list, it seems that no observation has
more than 10 IDs. Is there a method of generating a list
of all the IDs that appear in the list, so that this list
would only show each ID once?

Thanks!