Summary

In the document Managing users - Atlassian Documentation we refer to the abilities of administrators in Jira:

As an administrator, you can manage users directly in JIRA, or enable public signup so users can create their own accounts.

However Jira Project Administrators do not have this ability. You need to be either a Jira Administrator OR a Jira system administrator to manage this aspect.

Problem

This can be confusing for individuals trying to manager user access within Jira.

Suggested solution

We should be more explicit as to the exact global permission level needed to effect change here. In addition to re-wording this, it might help to add a header like that we see on the Managing global permissions - Atlassian Documentation.