I\'d like the user to be able to make multiple selections via the admin interface, and store the result as a list of comma-separated values. A select-multiple or a list of check
There is a django snippet which does just this: multiple choice model field. It says:
Usually you want to store multiple choices as a manytomany link to another table. Sometimes however it is useful to store them in the model itself. This field implements a model field and an accompanying formfield to store multiple choices as a comma-separated list of values, using the normal CHOICES attribute.