6.1 Dichotomous, bracketed keys are included for all taxa treated in the Flora of Nepal. Keys to genera, species and infraspecific taxa are given directly after the descriptions of family, genus and species respectively.
6.2 Keys are primarily designed for specimen identification, and so in most cases are artificial. The halves of each couplet should be unambiguous and contrasting. The order of characters in each couplet is the same, and should be from most diagnostically important to least important. Whenever possible, keys should include characters from both flowering and fruiting plants. Some taxa may be keyed out more than once.
6.3 Each character within a lead should be in a separate sentence.
6.4 Keys that contradict the descriptions are not allowed. To avoid this it is recommended that authors write keys after the descriptions have been written, and base the keys on the descriptions. If the two leads of a key have an unequal number of taxa, the lead with the fewer taxa is first.