The search facility works with whole words only and is case insensitive. Thus 'Diagram', 'diagram' and 'DIAGRAM' will all produce the same results.
Searching for part words such as 'dia' will not find 'diagram'.
Search on 'key' words rather than phrases.
Use abbreviations such as GWR, LNWR, LNER, SR etc. for the major railways, or the two letter RailRef code, or just one place name in the title of a company. A list of RailRef codes will be found in the Research section of the Society web site.
Most electronic products are supplied as Portable Document Format (PDF) files but some larger items may be supplied in TIFF or JPG image format. It is the customer's responsibility to obtain suitable software to read and make use of the files.