The outs statement simply copies the store snStore into the position in which it has been inserted. Most of the time this is used only in stores but it can be used in the context and output as well.
When using outs() in the context, the characters in the outs are included in index counts. See the example.
store(conskeys) "BCDFGHJKLMNPQRSTVWXYZ" store(vowelkeys) "AEIOU" store(allkeys) outs(conskeys) outs(vowelkeys) c using outs in the context outs(vowelkeys) + any(conskeys) > index(conskeys, 6)
The outs statement was introduced in Keyman 3.0.