Keep losing "sub" pose library after re-openning the file I am trying to categorizing my pose library into many "sub-libraries" such as mouth, eye, expression.  However, blender only keeps the last sub-library selected before closing the file, and loses all the other when the file reopened.

Currently, 2.79

What do I need to do?
Is there anything else I have to do to keep other sub-library before closing the file?

Will move to 2.8 after this project.  Hopefully, the principal can be transferred.

Thank you very much for your kind help.
See the zero next to the name of the new pose library in the first screenshot? That means it has no objects using it and so blender will thing this is unnecessary data and clean it up when the file is saved.

You can fix this by adding a 'fake user' to each pose library you want to keep using the button with a big F on it next to the pose library name when you have it selected.

This is very counter intuitive behavior.