A standard instruction that turns up from time to time in case management orders goes:
Legal submissions (if any) shall be in writing and accompanied by a copy of any Law Report(s) referred to. Three copies will be required by the Tribunal and should be brought to the hearing.
There are two problems with this: (i) it assumes you know what legal submissions and Law Reports are, despite the fact that many claimants (and quite a lot of respondents) will be representing themselves with no legal advice; and (ii) it’s silly.
What it means
‘Legal submissions’ are arguments about the law and its consequences. So if you say ‘my employer threw a waste-paper basket at me,’ that’s an assertion of fact (true or not). It’s not a legal submission, and it belongs in your witness statement. But if you say, ‘throwing a waste-paper basket at me was a breach of the implied term of trust and confidence in my contract of employment, and that was a fundamental breach entitling me to resign without notice,’ that’s a legal submission. You don’t need to put it in your witness statement, but you do need to say it at the end of the hearing – after everyone’s given their evidence – when you are telling the tribunal why you should win. Telling the tribunal why you should win is called ‘making submissions,’ and the part of that that is about what the law says and why it helps you is ‘legal submissions.’
Law reports are official printed accounts of cases that have been decided in the past, in this context mainly by the Employment Appeal Tribunal, the Court of Appeal or the House of Lords (or Supreme Court as it now is). For instance, if your employer says you didn’t resign because he threw a waste-paper basket at you but because you’d found another job – so it wasn’t constructive dismissal – you may want to remind the tribunal of Nottinghamshire County Council v Meikle  ICR 1. That’s a case in which the Court of Appeal said that a fundamental breach doesn’t have to be the only cause of the resignation for the resignation to count as constructive dismissal, so it would help you to argue your case in this situation.
So the instruction quoted means that if you want to say anything about the law, you must say it in writing, and you must bring three copies of what you want to say to the tribunal; and if you want to rely on any law reports, you must attach copies.
Why it’s silly
It’s silly, because the tribunal doesn’t actually mean it. The tribunal can’t properly stop you making oral submissions on the law if you need to, and they won’t try. It’s true that if you want to make a legal point that is at all complicated, it’s a good idea to make it in writing. But often you won’t. Many cases will run from beginning to end without any significant dispute about what the relevant law is: the dispute is about who did what, when and why, and whether it was fair. But minor questions of law may well come up unexpectedly, and both parties will certainly be allowed to say their piece on them.
The advice to bring 3 copies is unhelpful, too, because if you do decide to do some written submissions, you will actually need to take 5 copies with you: 3 for the tribunal, one for you, and one for the other side.