Virtual Hostnames
OUCHnet by default masks your IP from all users except staff. Registered users will automatically get a @user/{nickname} vhost.
Custom vHost
You can use hostserv as stated below, however you can also simply message an oper and request one.
Ouchnet uses hostserv, part of Anope services. You can find a list of commands available by using the /msg hostserv help command or using /query hostserv help in most clients.
If you need further assistance, you can request it from one of the opers in #help.
Please be patient as certain opers may not be online when you are. Request once in #help and a staff member will assist when available.