<emphasis>setting</emphasis>+<emphasis>operator</emphasis>+<emphasis>args</emphasis>
pairs. The <emphasis>setting</emphasis> is a Pazpar2 setting
(such as <literal>pz:id</literal>).
<emphasis>setting</emphasis>+<emphasis>operator</emphasis>+<emphasis>args</emphasis>
pairs. The <emphasis>setting</emphasis> is a Pazpar2 setting
(such as <literal>pz:id</literal>).