Definition
to officially consent to participate or cease participation in a structured plan or system
正式簽約加入（或退出）；同意加入（或退出）
She decided to contract out of the plan before the new project started.
她決定在新的項目開始之前退出該計劃。
The company is looking for partners willing to contract in to the program.
公司正在尋找願意加入該計劃的合作夥伴。
After evaluating all options, the team decided to contract in to the new community initiative.
在評估了所有選項後，團隊決定加入新的社區計劃。