Defined and addressed in the contract are the issues concerning the agreement. First and foremost, the rights and obligations of both parties must be defined in the written contract. Termination of contract and termination fees should also be included. Commonly, you will find the interest rates and other applicable fees included in the agreement.
"Investment banks" create loan agreements that cater to the needs of the investors whose funds they attempt to attract; "investors" are always sophisticated and accredited organizations not subject to bank regulatory supervision and the need to cater to the public trust. Investment banking activities are supervised by the SEC and their main focus is on whether the correct or proper disclosures are made to the parties who provide the funds.
In certain cases where you have repaid some installments of a previous student loan independently, you would be given the authority of branching away the Co-borrower. This is known as Co-Borrower Release and by doing so, you ensure that the loan repayment is entirely yours. This also puts you in a position where you are not hit by the Credit History of your Co-Borrower. Both of you are separate entities speaking from the loan perspective and you would hence need to take charge of repaying your loan off.
To stay clear of any legal involvement, both parties concerned must comply and honor all agreements made. Since the loan agreement serves as a contract and legal documentation, a violation of the terms and agreements can lead to a legal case and the written agreement can function as proof in court.