Applies To

Which Kinds of Things can this Property be used on? -- Collection: List Type: Whole Number Type

By default, a Property can be used on anything -- even when that is nonsensical. The result is that, when creating a new Thing, you get a messy list of lots of Properties, many of which are irrelevant.

So to keep that from happening, use this on your Properties. In most cases, a Property is really intended to only apply to Things or Properties, not both. So using this can keep you from having a long and confusing Property List.

This is an advanced Property, mostly because most user-defined Properties are intended to be used on Things, and you usually want to see all of your user-defined Properties as options. But serious programmers working in Querki may want to set this, especially if they are creating meta-Properties.