A Subpage is very similar to a Page, except for a few major differences:

• It can be any pixel size
• It can be shown/hidden within a Page

Each Subpage can only be added once to any specific Page, but can be used on multiple pages within your project.

This it the name of the Subpage. It must be unique - no Subpages or Pages can have the same name. The name must only contain alphanumeric characters and underscores. No spaces or other special characters are allowed.

When a Subpage is added to a Page, this is called a Subpage Reference. The Subpage Reference can be moved around a Page and has it's own set of properties separate to that of the actual Subpage that it references.