Re: JSON Functions and Operators Docs for v15

> +   same level are considerd to be <firstterm>siblings</firstterm>,

considered

> +    <productname>PostgreSQL</productname> specific functions detailed in

postgresql hyphen specific (as in the original)

These would all be easier to read with commas:

+        <parameter>expression</parameter> is NULL an
+        If <literal>WITH UNIQUE</literal> is specified the
+        If the input is NULL an SQL NULL is returned. If the input is a number
+        If <literal>WITH UNIQUE</literal> is specified there must not
+        is <literal>strict</literal> an error is generated if it yields no items.

There's a few instances of "space space" that could be condensed:

+   <function>json_scalar</function> functions, this needs to be  either <type>json</type> or
+        which  must be a SELECT query returning a single column. If