API: Clarify help text for cmstartsortkey and cmendsortkey parameters

diff --git a/includes/api/ApiQueryCategoryMembers.php b/includes/api/ApiQueryCategoryMembers.php
index 93918f7..5d40bac 100644 (file)
--- a/includes/api/ApiQueryCategoryMembers.php
+++ b/includes/api/ApiQueryCategoryMembers.php
@@ -345,8 +345,8 @@ class ApiQueryCategoryMembers extends ApiQueryGeneratorBase {
                        'dir' => 'In which direction to sort',
                        'start' => "Timestamp to start listing from. Can only be used with {$p}sort=timestamp",
                        'end' => "Timestamp to end listing at. Can only be used with {$p}sort=timestamp",
-                       'startsortkey' => "Sortkey to start listing from. Can only be used with {$p}sort=sortkey",
-                       'endsortkey' => "Sortkey to end listing at. Can only be used with {$p}sort=sortkey",
+                       'startsortkey' => "Sortkey to start listing from. Must be given in binary format. Can only be used with {$p}sort=sortkey",
+                       'endsortkey' => "Sortkey to end listing at. Must be given in binary format. Can only be used with {$p}sort=sortkey",
                        'continue' => 'For large categories, give the value retured from previous query',
                        'limit' => 'The maximum number of pages to return.',
                );