Listel (listing/grouping element)
The term Listel stands in GreenDesk for "listing element" (or "grouping element"). It is a database entity that manages a group of model elements.
Typically a Listel is used for grouping a list of related Blocks in the model, in which case it is usually just referred to as a block group. Authorised users can add and remove child block elements directly to and from block groups (although usually this is done via worksheets instead).
Most block group elements use 'indexed' mode, where every block has unique data.
Some block group elements use 'template' mode; they store a single block that represents all blocks in the group. This could be useful, for example, for efficiently representing a large list of identical windows on a building floor.
A Listel can also be used in combination with parametrics.
Usually you don't have to remove it, you should usually instead just "disable" it; it will then no longer be included in Expert System calculations, and can (depending on the current display options) also usually be hidden from view in worksheets if you choose.
For more information please see the section on enabling/disabling blocks under Blocks.