Family Historian User Group

If you want a very simple approach, add a Military Service fact to the individual with the relevant date range; support it with a source or sources linked to the images -- one source if it's a single document in four images, four sources if it's four separate documents with an image each. Maybe include some Notes summarising the contents of the documents.

For my father, for example I have:

If I have reasonable quality images of a war record (ie. one image per page/form), I quite often put them into a Word document, one per page, plus a title page describing the record (and source details, date etc**). Then I save that Word document as a PDF file, and then add that PDF file to the source record as a media file. This way I have the service records all in one document. By no means essential, just to my mind a bit tidier.

** I have sometimes even put footnotes on an individual page commenting on something (eg. mention of a relative, interpretation of some military terminology, explaining my interpretation of some unclear text on the original image).