*
* For API usage, in general,
* - any function _modifying_ the tree or tags (inserting or deleting
- * items, setting or clearing tags must exclude other modifications, and
+ * items, setting or clearing tags) must exclude other modifications, and
* exclude any functions reading the tree.
* - any function _reading_ the tree or tags (looking up items or tags,
* gang lookups) must exclude modifications to the tree, but may occur