Fun location structural indicator Probs??????

Dear

Pls any one give the solution for my below enquiry . In ECC6 i have created the St. Ind as XXX-XXX-XXXX-XXXX-XXXX-XXXX.

While attempting to create WA-WS as example the F.l agst the Str. Ind the system gives the F.L as badly WA--W.

Is it neccesary to maintain the -- code if we are not entered full codes.?

We would like to keep only one - symbol b/w F.L

Thenna