field links too long using writer document as template

field links too long using writer document as template

evening all! 
i'm trying to build some fillable templates in writer using either creator or forms as source. basically when you link the fields the link names are too long for the area in the document that the data is supposed to fill and it messes up the entrire document. i.e. field name: System Category goes in the document as <<system_category>>. but the space is only big enough for about 4 characters. hope that makes sense?
i want to be able to make the link for the field to only be 2 characters long so it kepps the merge document in shape.

any ideas how to achieve this?

regards

luke