diff --git a/Services.md b/Services.md
index 0223675..89a64db 100644
--- a/Services.md
+++ b/Services.md
@@ -10,6 +10,8 @@ REGISTER, IDENTIFY, LOGOUT, GROUP / UNGROUP / GLIST (grouped nicks), GHOST / REC
 
 REGISTER, INFO, LIST, DROP, SET (FOUNDER, DESC, channel toggles), ACCESS with AOP/SOP/VOP shortcuts, FLAGS (granular per-account flags), OP/DEOP/VOICE/DEVOICE, KICK, BAN/UNBAN, AKICK, ENFORCE, TOPIC, ENTRYMSG, INVITE, GETKEY, SEEN, CLONE, MODE and MLOCK, SUSPEND, NOEXPIRE. Registering a channel requires holding ops in it.
 
+Registration (of nicks and channels) refuses **look-alike names** — a name that mixes two alphabets (the classic `аdmin` with a Cyrillic `а`), is built entirely of homoglyphs imitating Latin, or hides invisible / text-direction characters. Genuine monolingual text passes, including accented French. This guards the registered-name namespace against impersonation, which a message-content filter on the ircd never sees.
+
 ## BotServ, channel bots
 
 Bot management, ASSIGN/UNASSIGN a bot to a channel, SAY/ACT, per-channel kickers (caps, flood, repeat, badwords), fantasy commands such as `!op`, and greet.