Which build in function is used by the checkbox "List children when object is looked at or opened"?

Also, what other build in functions are used by containers?

I'm not sure exactly what one it is, but....

here's all the built-in Functions:

https://docs.textadventures.co.uk/quest/elements/object.html (for the 'Object' Elements and also the Object Types / Types at the bottom too, these are the user-level's "groups/classes/mostly-container-types")
~~~AND~~~
https://docs.textadventures.co.uk/quest/elements/game.html (for the 'game' Object/Element/construct, which is a special/required construct/Object/Element that has game-wide/global settings, the 'pov' settings/controls, the 'start' Script, and the publishing info: author/version/firstpublished/category/difficulty/cruelty/description/etc, settings too)

^^^^^^^^
https://docs.textadventures.co.uk/quest/elements/
^^^^^^^^^
https://docs.textadventures.co.uk/quest/

maybe its...

https://docs.textadventures.co.uk/quest/attributes/hidechildren.html (toggle via setting: true/false)
https://docs.textadventures.co.uk/quest/attributes/listchildren.html (toggle via setting: true/false)

Which build in function is used by the checkbox "List children when object is looked at or opened"?

The question is a bit strange, and I can't answer it directly.

"List children when object is looked at or opened" sets the attribute listchildren. This attribute is used by the core function ListObjectContents().

Most of the settings in the editor take the form of attributes on a specific object, not functions.

Oh Thanks,
It is the list-/hidechildren boolean which is triggered by the mentioned checkbox.

listchildren is definitely what I looked for but not sure what hidechildren is for...

listchildren is definitely what I looked for but not sure what hidechildren is for...

In room descriptions:

With hidechildren true:

You can see a television, and a table.

With hidechildren false:

You can see a television, and a table (on which there is a bell, a book, and a candle).

The hidechildren attribute will be automatically set to false when the player does "look table", so that when they return to the room they won't need to look at it again to see what's on it.

Thanks, got it.