fix: refine only negative address filter behaviour

Author: 2color

src/ipips/ipip-0484.md

@@ -51,11 +51,12 @@ The proposed change is to add a `?filter-addrs` parameter to the `GET /routing/v
 - `unknown` can be be passed to include providers whose multiaddrs are unknown, e.g. `?filter-addrs=unknown`. This allows filtering providers whose multiaddrs are unknown at the time of filtering.
 - Multiaddrs are filtered by checking if the protocol name appears in any of the multiaddrs (logical OR).
 - Negative filtering is done by prefixing the protocol name with `!`, e.g. `?filter-addrs=!quic-v1,!tcp`. Note that negative filtering is done by checking if the protocol name does not appear in any of the multiaddrs (logical AND).
-- For an address to pass the filter, it must pass all negative filters AND match at least one positive filter.
-- Only multiaddrs that pass the filter are included in the response.
+- If no parameter is passed, the default behavior is to return the original list of addresses unchanged.
+- If only negative filters are provided, addresses not passing any of the negative filters are included.
+- If positive filters are provided, only addresses passing at least one positive filter (and no negative filters) are included.
+- If both positive and negative filters are provided, the address must pass all negative filters and at least one positive filter to be included.
 - If there are no multiaddrs that match the passed transports, the provider is omitted from the response.
 - Filtering is case-insensitive.
-- If no parameter is passed, the default behavior is to not apply filtering by network transports.
 
 ### Transfer Protocol Filtering