1915 Star Roll
From the card index you know the book number and page of the roll . You take this to an index at the PRO and you look up the first regiment served in and get the reference for the book number ad page. The Reference will be a WO 329/?? reference. This piece is ordered and generally comes up quick,it is a book and has numbered pages, you simply turn to the page number given on the card index and there you are.
in our example Moon's 15 star roll reference was WO329/2616, on arrival I turned to P309 as listed and there was moons entry. The information given from left to right was his service number, rank, name, date of entry and in brackets the theatre, 1 is france and then in the next column the date of discharge, in Moons case 8-6-18 and the relevant section of Kings regulations. The roll doesn't add any more than the card index.