[Koha] Adding MARC fields

[Amy Purvis]

I want to add some different MARC fields that are not part of the default to 
2.2.6.  Is there a way to do this?

I already know about the " + " sign to repeat fields that are part of the 
default new biblio record, but I want to know if there's a way, for example, 
to add an 050 field.

Thanks for any responses!

Amy