Does the “@” symbol have a special meaning when surrounding a CMake variable?

Question

While looking through the ITK source code I\'ve come across a number of files like this, which have the suffix .cmake.in and which define a number of variables

Answer 1

Files with suffix .in are usually intended for configuration via command configure_file. All sequences @NAME@ within such files are translated to value of variable NAME.

Outside of configure_file / string(CONFIGURE) symbol @ has no special meaning in CMake.