This is my unit database in an Excel spreadsheet. Also has trams/DLR. The first column on many pages has Y/N for seen/not seen and a filter at the top of the columns enable you to select required units only, you'll need to replace my Y/Ns for yours of course. I use X as a spacer to maintain gaps between subclasses when filtered. ps classes are generally in numerical order on the tabs with a few minor tweaks, like 318 and 320 are together on one tab followed by 319 on a seperate tab. I did this to keep the Scottish ones on one sheet without 319s in the middle. pps I highlight in yellow when seen and red for haulage. This allows for a colour filter to give a list of units required for haulage.