diff --git a/docs/usermanual-buffers-language-script-and-direction.xml b/docs/usermanual-buffers-language-script-and-direction.xml
index d98c79b7f..0235d2d39 100644
--- a/docs/usermanual-buffers-language-script-and-direction.xml
+++ b/docs/usermanual-buffers-language-script-and-direction.xml
@@ -136,10 +136,12 @@
determine which glyph to return.
- The safest approach is to add all of the text available, then
- use item_offset and
+ The safest approach is to add all of the text available (even
+ if your text contains a mix of scripts, directions, languages
+ and fonts), then use item_offset and
item_length to indicate which characters you
- want shaped, so that HarfBuzz has access to any context.
+ want shaped (which must all have the same script, direction,
+ language and font), so that HarfBuzz has access to any context.
You can also add Unicode code points directly with