diff --git a/lld/MachO/ld64-vs-lld.rst b/lld/MachO/ld64-vs-lld.rst
--- a/lld/MachO/ld64-vs-lld.rst
+++ b/lld/MachO/ld64-vs-lld.rst
@@ -4,6 +4,15 @@
 
 This doc lists all significant deliberate differences in behavior between LD64 and LLD-MachO.
 
+String literal deduplication
+****************************
+LD64 always deduplicates string literals. LLD only does it when the `--icf=` or
+the `--deduplicate-literals` flag is passed. Omitting deduplication by default
+ensures that our link is as fast as possible. However, it may also break some
+programs which have (incorrectly) relied on string deduplication always
+occurring. In particular, programs which compared string literals via pointer
+equality must be fixed to use value equality instead.
+
 ``-no_deduplicate`` Flag
 **********************
 - LD64: