A tracker can be thought of as a simple list of items. Each item has a number of fields to store values for the item.
There are numerous types of fields, depending upon what type of value is stored with the field. The values for fields are viewed and changed in either forms or table views. In particular, trackers support the following types of fields:
|Text||Single line of text.|
|Date & Time||A single date and time.|
|Logical||A logical or boolean value which can either be true or false.|
|Note||A variable length value which supports rich formatting, such as bold, highlighting, etc.|
|Tags||One or more tags (a.k.a. labels).|
|A single email address.|
|File||A single file attachment.|
|Attachment||One or more file or image attachments.|
|URL||A single URL link.|
|Comment||Comments to be associated with the item (e.g. tracking comments).|
|User||A single user who is registered to the tracker's workspace|
|Users||One or more users who registered to the tracker's workspace.|
There are also calculated fields, which automatically calculate their values from other fields' values. The values for calculated fields are determined from the calculated field's formula.
Calculated fields which reference other fields with undefined values may in turn result in an undefined value. However, functions such as ISTRUE() can be used to test for an undefined value inside a formula.
In forms, there is also the capability to clear an existing field value, making it undefined again. For trackers, clearing a value takes on a special meaning. For example, if a project task includes a “target completion date” field, explicitly clearing this field's value could mean the task initially had a specific completion date, but a completion date is no longer known.