@obs Number of observations.

@obsby Number of non-missing observations in a series or alpha, for each specified group.

@obsid Sequential index for the observation in the workfile.

@obsrange Number of observations in the workfile page .

@obssmpl Number of observations in the workfile sample.

@ones Matrix or vector of ones.

@option Option string provided in the exec or run command.

@otod Workfile observation to date string.

@otods Sample observation to date string.

@outer Outer product of vectors or series.