Is there a way to secure Level Sequences?

im scouting ahead for my work schedule — i remember from using sequences before
they seem to like to disappear or corrupt or break

i didnt notice enough about how or why

but is there something specific that has to be done to tidy it away for indefinite use?

like adding it to a master sequence or something

i need to start working on cameras next week but i dont get the pipeline enough
to be sure i wont waste the time and lose it