Initial visibility: currently defaults to autocollapse
To set this template's initial visibility, the |state=parameter may be used:
|state=collapsed: {{List of European capitals by region|state=collapsed}} to show the template collapsed, i.e., hidden apart from its title bar
|state=expanded: {{List of European capitals by region|state=expanded}} to show the template expanded, i.e., fully visible
|state=autocollapse: {{List of European capitals by region|state=autocollapse}}
shows the template collapsed to the title bar if there is a {{navbar}}, a {{sidebar}}, or some other table on the page with the collapsible attribute
shows the template in its expanded state if there are no other collapsible items on the page
If the |state= parameter in the template on this page is not set, the template's initial visibility is taken from the |default= parameter in the Collapsible option template. For the template on this page, that currently evaluates to autocollapse.
Template documentation