The thematic legends for ranges are automatically set to the word "to", for example "10 to 20" "20 to 30" etc. I need to write it with a dash instead: "10-20", "20-30". Can I change the default settings somewhere?
No, it is not possible to change it like that, but you have some options that might help.
Create thematic map and populate all fields in Customize Legend dialog
Then save this theme as a template with Save Customized Legend Text checked:
and then, when you use this template later, you must check Use Customized Legend Text
Of course, if next time your number of ranges is different (more than you have created in a template) then you have to adjust it manually for those extra rows (it will defaults to to again).
This could be managed if you have several customized templates with more or less defined ranges in it.
Second way would be that you prepare all your thematic legends and save your workspace. Then, open your workspace in your favorite text editor and find set legend commands and change to to dashes.
set legend layer 1 display on shades on symbols off lines off count on title auto Font ("Arial",0,9,0) subtitle auto Font ("Arial",0,8,0) ascending off ranges Font ("Arial",0,8,0) auto display off , "0 to 200" display on , <--- replace here 'to' with '-' "200 - 300" display on , "300 - 400" display on , "400 - 500" display on , "500 - 86.900" display on