diff --git a/stdlib/src/main/pascal/net.sockets.pas b/stdlib/src/main/pascal/net.sockets.pas
index 89afeac..64e9cff 100644
--- a/stdlib/src/main/pascal/net.sockets.pas
+++ b/stdlib/src/main/pascal/net.sockets.pas
@@ -27,6 +27,18 @@ unit Net.Sockets;
 
 interface
 
+{ ponytail: PORTING BOUNDARY — the constants and the sockaddr_in layout below
+  are LINUX x86_64 values.  Other targets differ and need a per-platform layer:
+    * macOS/BSD: SO_REUSEADDR=4, O_NONBLOCK=4 (impl section), and TSockAddrIn
+      starts with a sin_len:Byte before sin_family; MSG_NOSIGNAL does not exist
+      (use the SO_NOSIGPIPE socket option, or keep IgnoreSigPipe).
+    * Windows: a separate Winsock backend (ws2_32, WSAStartup, closesocket,
+      SOCKET handles, WSAGetLastError).
+  The helper API (TcpListen*/TcpConnect*/AcceptConn/RecvString/SendAll/Close/
+  MakeNonBlocking/IgnoreSigPipe) is the stable surface — callers never touch
+  these constants — so a future port changes only the implementation, not
+  consumers.  Add the platform split when a second target lands. }
+
 const
   { address families / socket types }
   AF_INET     = 2;
diff --git a/stdlib/src/main/pascal/security.guid.pas b/stdlib/src/main/pascal/security.guid.pas
index fe9138b..e3899f9 100644
--- a/stdlib/src/main/pascal/security.guid.pas
+++ b/stdlib/src/main/pascal/security.guid.pas
@@ -32,6 +32,13 @@ implementation
 uses
   StrUtils;   { TStringBuilder }
 
+{ ponytail: PORTING BOUNDARY — getrandom(2) is LINUX-specific (3.17+, glibc
+  2.25+).  FreeBSD has a compatible getrandom; macOS does NOT (use getentropy(3)
+  or SecRandomCopyBytes); Windows uses BCryptGenRandom.  When a second target
+  lands, dispatch c_getrandom per platform behind NewGuidRaw — the public API
+  (NewGuid/NewGuidRaw) stays put.  (/dev/urandom would cover all the Unixes but
+  not Windows, hence the syscall.) }
+
 { getrandom(buf, buflen, flags): fill buf with buflen random bytes from the
   kernel CSPRNG.  flags=0 reads from the same pool as /dev/urandom. }
 function c_getrandom(ABuf: Pointer; ALen: Int64; AFlags: Integer): Int64;