Information that Southern could supply and is wanted is potentially relatively simple. Information that is helpful and accurate.
The comment about emails above is so correct. I was paid £50 in vouchers last year because they acknowledged that their email responses were inaccurate and didnt answer the question. I hadnt asked for compensation, didnt want compensation, just raised it on their passenger forum as an example. They went away checked their email history and came back agreeing!
However things have not improved the other week after we were kicked off at Oxted I sent an email asking 4 questions about the incident. In their response they did not acknowledge any of my questions, they certainly didnt answer any of them, not even to say we dont know or we cant tell you, and the response gave the impression it was sent before being ended as there was no proper ending.
Their twitter feed is almost useless these days and its not the fault of the staff who are generally helpful but they are no longer allowed to tweet useful information about cancellations, short forms, late running. Instead of which we have to follow southermalachi who not only tweets this information but also manages to answer specific questions about services faster than the official team.
Now I know the official team have to answer queries etc, but if they tweeted the info in the first place they wouldnt get as many questions and maybe they need one feed to tweet train service info and the other to deal with questions.
A problem which will go away is the one of short platforms on the Uckfield line. Its a particular issue with the 18.05 ex London Bridge as its 8 carriages and several platforms can only take 5 or 6 carriages. However there is absolutely no info about this at London Bridge. Its not announced until the train has left the station which is too late. Almost every day there are people unaware of the fact they cant get off without moving down the train, and several times a week some of them are overcarried.
I accept SarahJs comments about guards announcements, some of them are better about making announcements than others, also if you are in the carriage the guard is in (on the 171 class anyway) the announcement is usually inaudible - I guess to avoid feedback.
The website is horrible to navigate and the bits you do want on the move are not available on the mobile site.
On the other side the tweeter team do get a hell of a lot of abuse for issues from passengers and that just isnt fair. They are doing a job, doing what they have been told to do, supplying the info they are given, they cant supply info they dont have, they cant wave a magic wand and improve the service so they dont deserve the abuse they get.