A 'no oral modification' clause states that the contract may be changed only by a signed writing. Its practical purpose is to:

解析

A no-oral-modification clause aims to prevent disputes over informal changes by requiring that any modification be made in a signed writing, promoting clarity and reliable records, an approach that aligns with sound change-order practice. Such clauses can still sometimes be overcome by clear conduct or waiver, so they do not make a contract absolutely unchangeable. They do not raise the price or eliminate warranties; they govern how changes must be documented.