doc: more of them for anynetwork

crates/network/src/any/mod.rs

@@ -535,9 +535,28 @@ impl alloy_consensus::Transaction for AnyTypedTransaction {
 
 /// Types for a catch-all network.
 ///
-/// Essentially just returns the regular Ethereum types + a catch all field.
-/// This [`Network`] should be used only when the network is not known at
-/// compile time.
+/// `AnyNetwork`'s associated types allow for many different types of
+/// transactions, using catch-all fields. This [`Network`] should be used
+/// only when the application needs to support multiple networks via the same
+/// codepaths without knowing the networks at compile time.
+///
+/// ## Rough Edges
+///
+/// Supporting arbitrary unknown types is hard, and users of this network
+/// should be aware of the following:
+///
+/// - The implementation of [`Decodable2718`] for [`AnyTxEnvelope`] will not work for non-Ethereum
+///   transaction types. It will succesfully decode an Ethereum [`TxEnvelope`], but will decode only
+///   the type for any unknown transaction type. It will also leave the buffer unconsumed, which
+///   will cause further deserialization to produce erroneous results.
+/// - The implementation of [`Encodable2718`] for [`AnyTypedTransaction`] will not work for
+///   non-Ethereum transaction types. It will encode the type for any unknown transaction type, but
+///   will not encode any other fields. This is symmetric with the decoding behavior, but still
+///   erroneous.
+/// - The [`TransactionRequest`] will build ONLY Ethereum types. It will error when attempting to
+///   build any unknown type.
+/// - The [`TransactionResponse`] may deserialize unknown metadata fields into the inner
+///   [`AnyTxEnvelope`], rather than into the outer [`WithOtherFields`].
 #[derive(Clone, Copy, Debug)]
 pub struct AnyNetwork {
     _private: (),