doc: Clarify the IPv4-mapped IPv6 lookups.

Credits to Andreas Metzler <eximusers@bebt.de>.

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index c21bc0dcc2d308e27ab986f9fe3b494feed12f46..f0bfd0eb8f431de99e4b7b9557379653ab98bcdb 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -6744,7 +6744,8 @@ the implicit key is the host's IP address rather than its name (see section
 
 .new
 &*Warning 3*&: Do not use an IPv4-mapped IPv6 address for a key; use the
-IPv4.  Such addresses being searched for are converted to IPv4.
+IPv4, in dotted-quad form. (Exim converts IPv4-mapped IPv6 addresses to this
+notation before executing the lookup.)
 .wen
 .next
 .new