The Radio Times indicates them for the main channels, and mentions for the other channels "ALL PROGRAMMES ON THE ABOVE CHANNELS ARE REPEATS UNLESS OTHERWISE STATED". Programmes that are not repeats are flagged as "New".
Ah O.K., I was thinking more of info. on EPGs.
They sometimes make a distinction about whether something is a repeat or not, by doing it by channel e.g. although this has been repeated to death on BBC1, it is new to BBC3 or Dave
As this topic has been posted in the 'Arms, it would be fair to consider it in a context outside the standard 'Fox, Firmware, or Freeview sections (the OP could have helped by stating context). As far as I can see that means published guides such as Radio Times etc, and I'm pretty sure they don't use symbols or abbreviations without also publishing a key. However, surely it's obvious that (quoting from the Telegraph)
BH2 only applies if BH1 is correct which it may not be, asking a non Freeview related question in the Freeview forum is wrong, asking a Freeview question in 'the Arms' is perfectly O.K. and as there is less likely to be a key in an EPG than a publication, BH1 is more likely to be wrong
I'm struggling to find an R on the Freeview EPG, but I have found examples in the programme details using S and AD. Can't find an SL either, not sure whether BBC NEWS carries a signed version of Breakfast these days.
BBC programs after midnight often have SL = Sign language e.g.
Nature's Weirdest Events
Synopsis 1/3. Chris Packham examines some of the world's weirdest natural events.
He visits the town plagued by a swarm of flying insects, meets friendly polar bears and more.
Start Wed Jan 23 02:20:00 2013 GMT