If you are G-lined from EmechNet, the reason will be stated in the line above/before the actual Quit/Kill message saying (G-Lined). If you are connecting through a BNC, this line might be filtered out. To find out the reason, you should connect to the shell, connect with a normal IRC client (such as irssi) from the same IP, and you will see the G-line reason. If you do not understand the reason you are G-lined for, you can contact #help for clarification. #help will, however, not provide you with any info regarding the g-line, such as duration, nor will it be removed upon request. All G-lines will last for however long they have been set, and you have to just wait for them to expire.
A K-line is a server-local ban, unlike a G-line, which is network-wide. K-lines are very rarely used on EmechNet, except for the !root@* K-line on most servers. IRCing from the root account of a server is very insecure and is , therefore, K-lined on EmechNet to protect the security of our users.