Info from Bernie Cullen:
"FTDNA made some major updates to the I-Y3548 (I-S17250) tree. Some I-P37 members have new haplogroup designations and some of you have new SNP results: go to Y-DNA Haplotree & SNPs and click SNP results near the top of the page. You will see a pop up window, some people will see new Y-HAP-Backbone SNP results at the top of the list. (Only people with Big Y results will see a new haplogroup designation and new SNP results, approximately 20 members had some update).
Some of the changes affected the Dinaric North portion of I-Y3548: In the I-A815 haplogroup, FTDNA added a new I-FGC92673 haplogroup which contains some existing branches and some new branches, including some people who were formerly in I-A815*
But the biggest changes were in I-PH908 (Dinaric South):
--FTDNA created a new branch called I-FTT63 which contains the large I-Z16983 branch, some smaller existing branches, some small new branches and some samples which were formerly placed in I-PH908 * and I-Y3548*
--FTDNA moved some small existing branches to I-PH908 , these branches were formerly directly under I-Y3548
--FTDNA created some small new branches below I-PH908
--FTDNA moved several samples from I-Y3548* to I-PH908*
Formerly 13 samples were placed in I-Y3548*.
As a result of these new SNP test results and new branches, only 2 samples are placed in I-Y3548* currently."