The Democratic Party has a charter and bylaws that, among other things, describe the function and organization of the Democratic National Committee.

The Democratic Party has a charter and bylaws that, among other things, describe the function and organization of the Democratic National Committee in Article 3 of the charter:

1. The Democratic National Committee shall have general responsibility for the affairs of the Democratic Party between National Conventions, subject to the provisions of this Charter and to the resolutions or other actions of the National Convention. This responsibility shall include: [list of duties]

You've asked in comments about antidiscrimination provisions. Those are defined for the whole party by the charter in Article 8 (as well as in other places):

1. The Democratic Party of the United States shall be open to all who desire to support the Party and who wish to be known as Democrats.

2. Discrimination in the conduct of Democratic Party affairs on the basis of sex, race, age (if of voting age), color, creed, national origin, religion, economic status, sexual orientation, gender identity, ethnic identity or disability is prohibited, to the end that the Democratic Party at all levels be an open party.

3. To encourage full participation by all Democrats, with particular concern for minority groups, Blacks, Native Americans, Asian/Pacifics, Hispanics, women and youth in the delegate selection process and in all Party affairs, as defined in the Bylaws, the National and State Democratic Parties shall adopt and implement an affirmative action program which provides for representation as nearly as practicable of the aforementioned groups, as indicated by their presence in the Democratic electorate.
   This program shall include specific goals and timetables to achieve this purpose.

4. This goal shall not be accomplished either directly or indirectly by the national or state Democratic Parties' imposition of mandatory quotas at any level of the delegate selection process or in
   any other Party affairs, as defined in the Bylaws; however, representation as nearly as practicable of minority groups, Blacks, Native Americans, Asian/Pacifics, Hispanics, women and youth, as indicated by their presence in the Democratic electorate, as provided in this Article, shall not be deemed a quota.

5. Performance under an approved affirmative action program and composition of the Convention delegation shall be considered relevant evidence in the challenge of any state delegation. If a state Party has adopted and implemented an approved and monitored affirmative action program, the Party shall not be subject to challenge based solely on delegate composition or solely on primary results.

6. Notwithstanding Section 5 above, equal division at any level of delegate or committee positions between delegate men and delegate women or committeemen and committeewomen, as defined in the Democratic National Committee Charter, Article Nine, Section 16, shall not constitute a violation of any provision thereof.

I believe the reference to the "Democratic National Committee Charter" in Section 6 of Article 8 is referring to the party-wide charter. Section 16 of Article 9 of the charter is exactly what's described in Section 6 of Article 8: it requires equal division between men and women in party committees and conventions.