clarify that restricted_writes do not include normal anti-spam heur…

…istics and other kinds of soft-restrictions.

11.md

@@ -127,6 +127,9 @@ Even if set to False, authentication may be required for specific actions.
 
 - `restricted_writes`: this relay requires some kind of condition to be fulfilled in order to
 accept events (not necessarily, but including `payment_required` and `min_pow_difficulty`).
+This should only be set to `true` when users are expected to know the relay policy before trying
+to write to it -- like belonging to a special pubkey-based whitelist or writing only events of
+a specific niche kind or content. Normal anti-spam heuristics, for example, do not qualify.
 
 - `created_at_lower_limit`: 'created_at' lower limit as defined in [NIP-22](22.md)