Update increment! documentation [ci skip]

activerecord/lib/active_record/persistence.rb

@@ -329,10 +329,10 @@ def increment(attribute, by = 1)
       self
     end
 
-    # Wrapper around #increment that saves the record. This method differs from
-    # its non-bang version in that it passes through the attribute setter.
-    # Saving is not subjected to validation checks. Returns +true+ if the
-    # record could be saved.
+    # Wrapper around #increment that writes the update to the database.
+    # Only +attribute+ is updated; the record itself is not saved.
+    # This means that any other modified attributes will still be dirty.
+    # Validations and callbacks are skipped. Returns +self+.
     def increment!(attribute, by = 1)
       increment(attribute, by)
       change = public_send(attribute) - (attribute_was(attribute.to_s) || 0)
@@ -348,10 +348,10 @@ def decrement(attribute, by = 1)
       increment(attribute, -by)
     end
 
-    # Wrapper around #decrement that saves the record. This method differs from
-    # its non-bang version in the sense that it passes through the attribute setter.
-    # Saving is not subjected to validation checks. Returns +true+ if the
-    # record could be saved.
+    # Wrapper around #decrement that writes the update to the database.
+    # Only +attribute+ is updated; the record itself is not saved.
+    # This means that any other modified attributes will still be dirty.
+    # Validations and callbacks are skipped. Returns +self+.
     def decrement!(attribute, by = 1)
       increment!(attribute, -by)
     end

guides/source/active_record_callbacks.md

@@ -202,11 +202,9 @@ The following methods trigger callbacks:
 
 * `create`
 * `create!`
-* `decrement!`
 * `destroy`
 * `destroy!`
 * `destroy_all`
-* `increment!`
 * `save`
 * `save!`
 * `save(validate: false)`