The scope of a mode primitive extends until a new mode primitive resets an option. The use of mode primitives will allow the network standard stream interpreter to treat them as null operations if the features are missing at a particular host, or to perform more detailed interpretation of the following data stream to achieve results. The drawing primitives may also then keep a standard format which need not be changed to incorporate new features. Overall modes which primitives could control would be intensity levels, or color selections for objects, in addition blinking of objects should be provided. For vectors, the additional facility for drawing dashed lines is necessary.
Character strings require another set of specification.
The convention for the beam is usually that it is in the center of the rectangular area defining a character's boundaries. The beam position is usually undefined at the finish of drawing a character string. A strong exception is taken to the exclusion of form control characters from strings. The appropriate characters could be extracted at interpretation time to provide the necessary information to display more complex strings. I believe the Multics conventions described in reference 1 will suffice.