I’ve tried searching this topic unsuccessfully, and such complicated directions as I could find in the Dorico help pages don’t work. How do you replace repeated identical bars in parts with the little ditto sign and number them so the players can keep track of where they are? Then keep it only in the parts, not the score? I’m using version 6.2. Thanks!
This is called Numbered Bar Regions
and Bar Repeats
Please consider that classical musicians hate bar repeats 
Thanks, Vadian. This isn’t for classical musicians; it’s for high school bands!
Unfortunately, this part is not yet possible, but it’s been requested many times.
Actually it is possible, of course with a detour.
Create additional players, copy the music and apply the ditto signs – in German we call these loafers – use them for the individual parts, and hide them in the score. The disadvantage is that the score and the parts are not in sync.
Alternatively, duplicate the flow, or even the project file. Which still has the same drawback of course, losing the automatic connection between score and part.
Thanks, everyone, for the replies. I’ve decided that the space saved in the parts isn’t worth all the complicated hoops to jump through, so I’m going to leave the notes in place and just number the measures to help the players keep their place. 