So are 'parlies' about stations or sections of railway? A few years ago after Cross Country trains stopped running to Brighton they were meant to run a service covering a couple of sections of railway in West London. They never ran any trains, but got away with running a once-a-week bus from Wandsworth Road to Ealing Broadway via Kensington Olympia (I caught it once just for a laugh). I can't think of another rail replacement bus that actually replaced a non-existent train service! Eventually another train company started running an actual train, but only from Wandsworth Road to Kensington Olympia. Perhaps someone can explain what happened next - are both sections covered by new services, or has someone quietly forgotten about them?
And then there's the Lifford Curve in south Birmingham. This section of railway does not have a 'parly' train, or rail replacement bus, but on Saturday, for the first time in about 10 years, it had a public train service - ironically operated by Cross Country. I actually managed to have a ride on this from New St to Tamworth and back. Can anyone explain why there is no requirement for a 'parly' as it had a passenger service when it opened in the 1890's?