He stopped a passing guard, but didn't dare mention platform nine and three-quarters. The guard had never heard of Hogwarts and when Harry couldn't even tell him what part of the country it was in, he started to get annoyed, as though Harry was being stupid on purpose. Getting desperate, Harry asked for the train that left at eleven o'clock, but the guard said there wasn't one. (Harry Potter and the Sorcerer's Stone)
In this context, I guess, ‘asked for’ seems to mean ‘asked about’ the train. But I’ve not found the usage yet. Would you let me know what the phrase exactly means in this case?