A non-standard form of appointment is a contract that does not follow the typical structure and clauses that known contracts have. As a custom contract, it would have different clauses specifically set for the particular needs of the project without offering the reassurance of terms that industry  standard contracts do.

Non-standard forms of contract are extremely risky if things at some point go wrong and that contract did not cover adequately the handling of the specific issue. They are not cost effective as more work is required from a legal department/third party before they are considered ready for use.