A portal link allows you to direct your members to your Community's home page.
The Recruitment URL allows you to direct your recruitment traffic to a URL for the user signup and profiling, where there are questions and criteria defined to filter the members accordingly.
The tracking variable is stored in a cookie. In general, you can use whatever symbols that browser cookies can handle. However, keep in mind that the link is in the URL - so if you have characters like "&" etc. they need to be HTML Escaped.
Our recommendation is to not put any special characters in the value of the source field. Values like "&" and "?" interfere with the HTML URL and may not be captured correctly.
This feature is available with the following license :