Rule 1 of CPC : Rule 1: Notice of admission of case.

Explanation using Example

Example 1:

Ravi files a civil suit against Shyam claiming that Shyam owes him Rs. 50,000 for goods supplied. Shyam, in his written statement, admits that he owes Ravi Rs. 30,000 but disputes the remaining Rs. 20,000. By admitting part of Ravi's claim in writing, Shyam has complied with Rule 1 of Order XII of the Code of Civil Procedure, 1908.

Example 2:

Meera sues her neighbor, Anil, for encroaching on her property by building a wall that extends into her land. Anil, in his defense, admits in writing that he did build the wall but claims it was done with Meera's consent. By admitting the construction of the wall, Anil has acknowledged part of Meera's case as per Rule 1 of Order XII of the Code of Civil Procedure, 1908.