A role is defined with the \"Declaring a space member role\" form. It asks for a label, a short name such as \"member\", a heading such as \"Members\" under which holders are listed, and the tier — maintainer, member or observer, with observer as the default.

The definition also fixes how a grant is written: the statement that says someone holds the role, either from the person to the space (\"Alice is a member of X\") or from the space to the person (\"X has member Alice\"). Optionally it names a template for making grants, which is what puts an \"add …\" button on space pages.