Clarify 'treesize'.

1 files changed, 4 insertions, 3 deletions

diff --git a/doc/db.md b/doc/db.md
index 9b7f9d3..925891e 100644
--- a/doc/db.md
+++ b/doc/db.md
@@ -25,12 +25,13 @@ Two files (catlfish names in parentheses):
 
 - treesize (treesize)
 
-  filename is static, contains one line -- the number of entries in
-  the database
+  filename is static, file contains one line -- the number of entries
+  in the part of the database up to and including the last entry in
+  the last published tree, like a "current pointer"
 
 - index (index)
 
-  filename is static, contains one line per entry -- the leafhash
+  filename is static, file contains one line per entry -- the leafhash
 
 Three directories, "bucketed" in three levels, one file per database
 entry (catlfish names in parentheses):