RTT seems to report it as "L" for trains that have departed, but A for trains that have not yet departed.whereas RTT reports it as "L"
The train planning system (where the schedules are generated, which in turn drive what's shown in journey planners and on displays) has it down as platform "A", hence that's what is displayed before the train arrives.RTT seems to report it as "L" for trains that have departed, but A for trains that have not yet departed.
This suggests to me that different systems inside network rail are not consistent with each other.
The station map on National Rail Enquiries just says "Lift to Merseyrail platform" and doesn't show a number or letter.
That was pretty common across the former Regional Railways network. To this day plenty of our smaller stations in the East Midlands don't use platform numbers.Traditionally (until the 1990s at least) Merseyrail station platforms weren't numbered other than the multiplatform city centre stations (i.e. Central, Moorfields, James St plus Hamilton Square and Southport), it was all just signed by destination. I think they all are now though, done alongside the installation of proper CIS at the outlying stations.
And these days the main departure board in Lime Street Station includes a separate small board for Mersey rail trains.The station map on National Rail Enquiries just says "Lift to Merseyrail platform" and doesn't show a number or letter.