I have 2 questions:
1. If a 5-20RA receptacle was installed in full 1complience of 26-710(b), and someone was to at another date plug into this circiut a "motor-only" applience (for example a vacuum cleaner), would this violate 28-200(b)?
2. If section 14 would allow a larger overcurrent device than section 28 the which size would you choose.

Crash,

A)No there would be no violation.

Rationale for Rule 28-200.

Because most motors have an inrush current approximately six times the motor full load current, the overcurrent device shall be of sufficient ampacity to avoid nuisance tripping.

Intent for Rule 28-200.

We intend to allow the trip values shown in Table D12, but if fuses are used and the percentage value in Table 29 will not allow the motor to start, this value may be increased. Table 26 reflects the values shown in Table 29 and is a handy guide. Appendix B provides guidance on sizing of the overcurrent protection.

B)Personally, The lower value.

Thanks, Tony.
I was thinking more along the line, that if the FLA was not known, or Table 29 indicated an over-current value of less than 14A. Then the notwithstanding clause in 28-200(b) would still allow this motor to be connected to a standard 15A receptacle supplied by a 15A O.C. . But what if a T-Slot receptacle and 20A O.C. were installed in lieu of the standard. 28-200(b) only specifies allows up to 15A.