Works-cited-list entries in MLA style are based on the template of core elements. Each element should generally be included in your works-cited-list entry when relevant to the work you’re documenting. Sometimes, however, you may need or want to supply additional information about a work. You can do so by adding supplemental elements to the template. A supplemental element should be inserted after the Title of Source element if it does not pertain to the entry as a whole. Otherwise, it should be inserted at the end of the entry. Exceptionally, it may be placed between containers if it applies only to the preceding container and not to the container following it.
For more details about supplemental elements, as well as examples, see the ninth edition of the MLA Handbook.