You can ask for help from anyone who agrees to get into debt with you. The document is just a list of things people helped with each other. They owe nothing to each other, unless the helped one succeed financially, and that success is connected to that help. So you can return that debt. People co-invest because of trust and belief in projects.
These days, there are many people, who just help other people out of good will or heart, and do not record that contribution. This way, when the other person that succeeds because of that, is not obliged to help them in return.
Basically, this debt document would be like a ledger (like the one we develop here at 0oo), that enables people to ask for other people's help, even though they have no money to pay for it (e.g., for expectation of success of the project that they ask the help for), under the conditions, that if the help the borrower goes into agreement to pay it back, when possible.
If that kind of debt document would be a more known instrument, people could get many things done without money, for the credit of another person, i.e., belief in your project or future success.