Line breeding is breeding related animals to one another either to prove genealogy or lock in a trait.
Inbreeding and linebreeding really isn't a much of an issue as people make it out to be in reptiles. I probably wouldnt inbreed for 30 generations consistently, but 3-5 or even more generations really will not have a negative impact on your animals unless you already have some kind of underlying cause.
And welcome to bp.net![]()