Eandrew, article 310-16 is correct. The conductors are rated at 100% and are not the issue in the 80% value. The 80% concerning continuos loads are for OCPD,s and the heat at the connection. If the OCPD is rated for 100% this will not be an issue. I assume by your use of the dash you are refering to the 99 code and if this is the case see 384-16d
I was thinking that the 80% and 125% related to different things. It is clear to me now. Continuous loads are limited to 80% of the overcurrent device rating. A little algebra and you have an overcurrent device must be at 125% of the continuous load. got it, thanx.