Numbering chapters, headings and subheadings is not mandatory, but the heading levels must be clearly distinguished. If you do number the headings, the numbering must be sequential and accurate.
Capitalization of same-level headings must be consistent. You can use title case or sentence case, but must use the same case for all headings of the same level. This also applies to captions of tables, figures, etc.
Running Headers / Running footers
Running headers are a navigational aid to the reader in large documents. Chapter titles as well as numbers are normally included in a running header in order to give the reader an idea of the chapter content.
It is not necessary to have running headers or running footers in your thesis, other than for page numbers. If you choose to have a running header, it must have only chapter titles (and chapter numbers, if applicable), or chapter subsections. Information other than this is not acceptable in a header or footer. In addition, placement of the running header must conform to the Chicago Manual of Style (CMoS) requirements; i.e. it must not be used on the title page or dedication pages, or on the first pages of sections in the preliminary pages, first pages of chapters, and any pages containing only illustrations or tables. The running header must be placed top centre or top right-justified. See CMoS 17, 1.11 and 1.12. If you are not familiar with correct use of running headers, we recommend you don't use them.