Every document instance requires a name that should uniquely identify it within its doctype.

Within a doctype the name of a document instance is recommended to be unique.

This uniqueness of a name within its doctype is not enforced. Documents may be added to a search by specifying a couple of spaces. But it is good practice to check this uniqueness within a space. Typically the title of a Wiki page is identical with the name. But there are exceptions from this rule, to make the documentation process easier.

Names must not contain parentheses or brackets of any kind.

Resources

Name and Title: The purpose and the differences between the name and title property of a doctype.
Title: The title of the Confluence page.
Nameless Documents: Feature to derive a document's name from its title.
Short Name: A shorter or abbreviated name of the document.