St Albans at one time had three independent railway stations, owned by the London and NW Railway on the branch from Watford, the Great Northern station on the branch from Hatfield and finally the Midland Railway station on the 'London Extension' from Bedford to St Pancras.
At first it seems that public timetables differentiated between the three by adding (LNWR), (GNR) or (MR) as needed. The GNR station became known as 'London Road' due to it's proximity to the highway of that name and eventually closed to passengers in 1951.
There was no distinction between the LNWR station and the MR station until both came under the LMS following the 1923 grouping, when the LNWR terminus was labelled 'St Albans Abbey' and the MR station 'St Albans City'.
The latter, like the 'Elstree and Borehamwood' station up the line, was called just 'St. Albans' for a while after privatisation, but was renamed with the 'City' suffix after a senior TOC member had visited the preserved St Albans South box and seen our original BR 'Running-in' board with the 'City' on it!