Ensure objects have an objectclass property

1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index 7b299aa..f37d884 100644
--- a/README.md
+++ b/README.md
@@ -112,7 +112,7 @@ A rule is a string composed of five fields separated by `:`. The fields are the
 
 1. The name of the user that must be bound (logged in) for the rule to apply. May contain wildcards such as `*` (see the format used by Go's `path.Match`). The special name `ANONYMOUS` applies to clients before they bind to an LDAP entity.
 2. The groups that the user must be a part of, separated by spaces. Wildcards may also be used. If several groups (or wildcard group patterns) are specified, for each pattern the user must be part of a group that matches it.
-3. The action, a subset of `bind`, `read`, `add`, `delete`, `modify` separated by spaces.
+3. The action, a subset of `bind`, `read`, `add`, `delete`, `modify`, `modifyAdd` separated by spaces. `modifyAdd` is a special value that only authorizes modifications that add new values to a given attribute. This can be used to allow users to add other users to a group but not remove users from the group.
 4. The target entity of the action as a pattern that may contain wildcards. The special word `SELF` is replaced by the entity name of the bound user before trying to match.
 5. The allowed attributes for a read, add or modify operation. This is specified as a list of patterns to include and exclude attributes, separated by spaces. A pattern that starts by `!` is an exclude pattern, otherwise it is an include pattern. To read/write an attribute, it has to match at least one include pattern and not match any exclude pattern. Delete operations do not check for any attribute, thus as soon as `delete` is included in the allowed actions, the right to delete entities is granted.