Relevant excerpts from the 2017/18 ISU Challenger Series Announcement:
http://static.isu.org/media/520340/cs2017-18_announcement-final.pdf
The International Competition as part of the ISU Challenger Series in Figure Skating must include entries in at least 3 disciplines from a minimum of ten (10) different ISU Members, in all disciplines combined.
In addition, the minimum number of entries per discipline are as follows:
Men / Ladies: minimum of eight (8) entries each, from at least four (4) ISU Members;
Pair Skating: minimum of five (5) entries from at least three (3) ISU Members;
Ice Dance: minimum of six (6) entries from at least four (4) ISU Members.
For the criteria relating to the awarding of the special ISU World Standing Points for the ISU Challenger Series in Figure Skating please refer to paragraph 9 below.
9. ISU WORLD STANDING POINTS For the ISU Challenger Series in Figure Skating higher ISU World Standing Points than for “regular” International Competitions shall be awarded. Each competition of the ISU Challenger Series in Figure Skating will be awarded with the following scale of points (in brackets for comparison is indicated the number of points for “regular” International Competitions):
Men & Ladies
1st place 300 points (250)
2nd place 270 points (225)
3rd place 243 points (203)
4th place 219 points (182)
5th place 198 points (164)
6th place 178 points
7th place 160 points
8th place 144 points
Pair Skating
1st 300 points (250)
2nd 270 points (225)
3rd 243 points (203)
4th 219 points (182)
5th 198 points (164)
Ice Dance
1st 300 points (250)
2nd 270 points (225)
3rd 243 points (203)
4th 219 points (182)
5th 198 points (164)
6th 178 points