Contracts for the D/s lifestyle are fairly common in the BDSM community. For those who aren't familiar with D/s contracts, they are basically a symbolic formality where both the Domme and sub agree to the terms and expectations of the relationship. While these don't hold any legal weight, they symbolize commitment and dedication to the lifestyle and there are many who hold their contracts quite dear to their hearts because of that.
Basically, contracts cover what the Domme expects of her sub as well as additional measures to cover misbehavior, punishments, under what grounds can the sub leave or be dismissed, etc. On the sub's side, he agrees to conduct himself by the terms of the contract in exchange for certain behaviors from his Domme. Contracts will often include hard-limits (things that either party will not do under any circumstance).
Contracts may range from very simple to very intricate and in some cases will be so thorough that they will include the set of rules and applicable punishments.
Other common inclusions are renewal dates, how the contract may be revised/negotiated upon in the future, and special circumstances allowing one or both parties additional freedoms if necessary.
I have written several contracts over the years and have been asked to write contracts for others (usually I would compose a rough draft that they would fine tune). For some reason the idea of committing things to print and signing my pledge of allegiance to the relationship turns me on quite a bit.
The contracts I have written have usually been very much in favor of the Domme (and I think this is why they have enjoyed my writing of these quite a bit).
A few examples of Domme-favoring characteristics:
-Provisional rule changes. If the Domme finds it necessary to enact additional rules, regulations, or restrictions she may do so at any time (with or without the sub's approval) but she must state it officially and commit it to writing. Upon completing the statement and written terms these rules will be considered in effect from that point on and may be added to the contract at the next renewal date.
-Asymmetrical renewal periods. Rather than having both parties renew at the same interval, the Domme will renew more frequently than the sub. e.g. She will review the contract and make any necessary changes and renew every 2 months while the sub will only be allowed to evaluate the contract and renew every 6 months.
-The sub may not leave the relationship unless he is dismissed by the Domme. If he is dismissed due to misconduct there may be additional penalties involved.