Docs: NR: revise description of `head-separation'

diff --git a/Documentation/notation/spacing.itely b/Documentation/notation/spacing.itely
index bd844e3ebe5fb7aa81b138ef3e86e5677f7c21b0..6ef417f3176a7639080729580ff51516839a0b45 100644 (file)
--- a/Documentation/notation/spacing.itely
+++ b/Documentation/notation/spacing.itely
@@ -248,8 +248,12 @@ footer.  Default: @code{4\mm}.
 @item head-separation
 @funindex head-separation
 
-Distance between the top-most music system and the page header.
-Default: @code{4\mm}.
+Distance between the header markup (@code{oddHeaderMarkup} and
+@code{evenHeaderMarkup}) and the title markup
+(@code{bookTitleMarkup}, @code{title}, and others).  If the header
+markup and title markup are not present, it is the distance
+between @code{top-margin} and the spot where the title markup
+would normally appear.  Default: @code{4\mm}.
 
 @item page-top-space
 @funindex page-top-space