estat (svy)
Estat (svy) refers not to a single command, but to a whole series of commands specifically related to doing estimation work following survey data. The UCLA website offers a basic intro to svy commands with Stata. Additionally, Stata offers an [SVY] manual, but Reed does not own a copy for the community. Additionally, typing help estat (svy) into the Command window will bring up Stata's built-in help on the subject.