The more I use this program the more I like it.

How do I turn off the indentation line which enable the code all to be lined up.

Not sure this is a good description. Its the - vertical lines running down from each tab.

What is the correct name?

Thanks

Try to uncheck "Indent guides" checkbox at Settings dialog => Editor => Editor theme => Editor tab.

Thanks very much mdegtyarev

I would never have found that by myself