The second column represents the so-called constraints, which
determine the orientation and size of geometric objects.
The corresponding CAD command is the REMEMBER-command. Possible
constraints are, for example, parallelism, perpendicular,
tangentiality (all orientated constraints) and distance or
radius (constraints determining the size).
Each of these constraints
defines a relation between two or more objects, but none of
them is distinguished. These constraints are considered with
manipulations and thus remain in the construction.