Writing as a creative art is meaningful, and as a form of self-expression it perhaps allows us to communicate when spoken words are inadequate.
In dreams we may learn how to communicate with ourselves in differing ways. Computers are a way of writing just as much as pens.
Transcribing information in a dream signifies committing it to memory.
At those times when we are arranging legal matters or agreements, but are actually not sure if we are doing the right thing, our signature can appear in dreams as obliterated or illegible.