169/168, is a superparticular ratio measuring about 10.3 cents. It is the difference between 13/12 and 14/13 semitones, and also between 224/169 and 4/3 perfect fourths.
169/168 is tempered out in a 13-0-2-8 chord of 19edo, which is a symmetrical relative to itself - it is the same when inverted. Such a chord consists of a stack of 16/13 - 13/12 - 16/13, which also intertwine two 4/3s between the 1st and 3rd, and 2nd and 4th notes. Tempering out 169/168 means that 14/13 can appear in this chord as well as 13/12.