Action name: MakeStructVarThis command declares a variable of the specified structure type.
IDA will ask you to choose a structure type. You must have some structure types defined in order to use this command.
If the target assembler supports it, IDA will display the structure in terse form (using just one line). To uncollapse a terse structure variable use the Unhide command.
You can also use this command to declare a structure field in another structure (i.e. nested structures are supported too).
See also Edit|Structs submenu.