You can check that anonymous marking have been enabled by visiting the assignment overview screen of your assignment. This is usually done by:
As shown in the example below, the usual columns of students' names have been replaced by a new column entitled Identifier, within which a Participant number is displayed.
Please note that this number is automatically generated by Moodle and does not correspond any other data or information held by the University of Bath e.g. Bath username, Student ID in SAMIS etc.