ACBL published a document earlier this year (Convention Charts 2020) showing permissible bidding conventions for different types of games and competitions.
Club games will usually be conducted under the Open Chart. However, restricted games, such as mentor games should use either Basic or Basic+. Unit 431 mentor games will henceforth be using Basic+.
Here is an excerpt from the ACBL document, showing both the Basic and Basic+ Charts, so you can see the differences between them.