Determining user access to groups generated in a closed online system based on categories determined for the groups

A computer program product comprising a non-transitory computer-readable storage medium having instructions encoded thereon that, when executed by a processor, cause the processor to:

• maintain information identifying a set of users at an online system, wherein each user in the set is a member of an organization;
• maintain a list of categories, each category associated with one or more access rights regulating access to content by users of the online system and each category identifying a relationship between users authorized to access content associated with the category and the organization;
• receive a request from a user in the set of users to establish a group of users, the group including one or more users from the set of users;
• identify one or more categories from the list of categories to the user;
• present the identified one or more categories to the user;
• receive a selection of a category from the identified one or more categories from the user;
• store information describing the group of users and associating the selected category of access rights with the group of users;
• receive a request from a user of the group to invite a first entity outside of the set of users who are members of the organization;
• generate an invitation to the group, the invitation including information identifying the online system, information identifying the group, and instructions that, when executed, obtain information for communicating with the first entity, the invitation being invalidated after being executed a single time by the first entity to request to join the group;
• communicate the invitation to a client device associated with the first entity;
• receive, from the first entity, identifying information for the online system to communicate with the first entity in response to the invitation communicated to the client device associated with the first entity, the first entity remaining outside of the online system;
• and
• receiving, by the first entity, content associated with the group without being a user of the online system.