The documentation for versions 2.21 and older can be found here.
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How many field types exist?
Currently, thirteen field types exist.
Those field types are:
Date input (old)
Date input (new)
Retrieved from LDAP
Why should I use the profile field type Multiline text ?
It allows users to enter text. Users can also use line breaks and create lists. It's just a bigger text field which is not limited to a single line. It's a great field type for a short user introduction.
The multiline text also allows users to enter links. Those links will become clickable.
How to use line breaks in Multiline text when syncing via XML
As the name suggests, the Multiline text field type offers the ability to store multiple lines of text in a profile field. If you wish to use this profile field via XML, here's what you need to consider: