You can add specification references to your drawings using the free NBS Annotator tool to copy and paste specification clause references into your drawing. As this works through the clipboard it will sit on top of any Microsoft Windows application.
NBS Annotator is part of a suite of collaborative programs called NBS Tools and can be downloaded for free by non-NBS subscribers to facilitate collaboration.
Notes for software vendors or AEC practices with in-house development teams:
There is a documented, open API that allows software developers to embed in NBS annotation tools in any software product.