Merge #20090: [doc] Tiny followups to new getpeerinfo connection type field

41dca087b73a3627107603694f5a982ea2a53189 [trivial] Extract connection type doc into file where it is used. (Amiti Uttarwar)
3069b56a456d98fca7c4a4ccd329581bd1f0b853 [doc] Improve help for getpeerinfo connection_type field. (Amiti Uttarwar)

Pull request description:

  two commits addressing small followups from #19725

  * first commit adds a clarification in the release notes that this field shouldn't be expected to be stable (suggested by sdaftuar in https://github.com/bitcoin/bitcoin/pull/19725#issuecomment-697421878)

  * second commit moves the `CONNECTION_TYPE_DOC` object out of the header file to reduce the size of the binary (suggested by MarcoFalke in https://github.com/bitcoin/bitcoin/pull/19725#discussion_r495467895, he tested and found a decrease of 10kB)

ACKs for top commit:
  achow101:
    ACK 41dca087b73a3627107603694f5a982ea2a53189
  laanwj:
    Code review ACK 41dca087b73a3627107603694f5a982ea2a53189

Tree-SHA512: a555df978b4341fbe05deeb40a8a655f0d3c5c1c0adcc1737fd2cf61b204a5a24a301ca0c2b5a3616554d4abf8c57074d22dbda5a50d8450bc22c57679424985

2 files changed, 16 insertions, 10 deletions

diff --git a/src/net.h b/src/net.h
index 40eab889a6..55de7afa05 100644
--- a/src/net.h
+++ b/src/net.h
@@ -115,17 +115,12 @@ struct CSerializedNetMsg
     std::string m_type;
 };
 
-const std::vector<std::string> CONNECTION_TYPE_DOC{
-    "outbound-full-relay (default automatic connections)",
-    "block-relay-only (does not relay transactions or addresses)",
-    "inbound (initiated by the peer)",
-    "manual (added via addnode RPC or -addnode/-connect configuration options)",
-    "addr-fetch (short-lived automatic connection for soliciting addresses)",
-    "feeler (short-lived automatic connection for testing addresses)"};
-
 /** Different types of connections to a peer. This enum encapsulates the
  * information we have available at the time of opening or accepting the
- * connection. Aside from INBOUND, all types are initiated by us. */
+ * connection. Aside from INBOUND, all types are initiated by us.
+ *
+ * If adding or removing types, please update CONNECTION_TYPE_DOC in
+ * src/rpc/net.cpp. */
 enum class ConnectionType {
     /**
      * Inbound connections are those initiated by a peer. This is the only
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index 43c525b6a0..b81e6414a5 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -29,6 +29,15 @@
 
 #include <univalue.h>
 
+const std::vector<std::string> CONNECTION_TYPE_DOC{
+        "outbound-full-relay (default automatic connections)",
+        "block-relay-only (does not relay transactions or addresses)",
+        "inbound (initiated by the peer)",
+        "manual (added via addnode RPC or -addnode/-connect configuration options)",
+        "addr-fetch (short-lived automatic connection for soliciting addresses)",
+        "feeler (short-lived automatic connection for testing addresses)"
+};
+
 static RPCHelpMan getconnectioncount()
 {
     return RPCHelpMan{"getconnectioncount",
@@ -119,7 +128,9 @@ static RPCHelpMan getpeerinfo()
                             {RPCResult::Type::BOOL, "inbound", "Inbound (true) or Outbound (false)"},
                             {RPCResult::Type::BOOL, "addnode", "Whether connection was due to addnode/-connect or if it was an automatic/inbound connection\n"
                                                                "(DEPRECATED, returned only if the config option -deprecatedrpc=getpeerinfo_addnode is passed)"},
-                            {RPCResult::Type::STR, "connection_type", "Type of connection: \n" + Join(CONNECTION_TYPE_DOC, ",\n") + "."},
+                            {RPCResult::Type::STR, "connection_type", "Type of connection: \n" + Join(CONNECTION_TYPE_DOC, ",\n") + ".\n"
+                                                                      "Please note this output is unlikely to be stable in upcoming releases as we iterate to\n"
+                                                                      "best capture connection behaviors."},
                             {RPCResult::Type::NUM, "startingheight", "The starting height (block) of the peer"},
                             {RPCResult::Type::NUM, "banscore", "The ban score (DEPRECATED, returned only if config option -deprecatedrpc=banscore is passed)"},
                             {RPCResult::Type::NUM, "synced_headers", "The last header we have in common with this peer"},