What happens if a user spends a long time in creating a static group of contacts/records only to discover that they made it private and it can't be shared with colleagues?

One little oddity in Sage CRM is that once a group has been created as a private group the interface doesn't provide a mechanism to make it public.

This is the point that you discover that Groups (target lists) are actually held as meta data in the custom_reports table.

The field in the custom_report table we need to access is the repo_privateuserid.

If repo_privateuserid is set to 0 then all users should be able to see it.
If it is set to -1 then only Info Admin and above could see it.

To make the field public we would have to run an SQL statement against the table:

e.g.

update custom_reports
set repo_privateuserid = 0
where repo_name = 'MyGroup'