Why were new guidelines adopted?
From ISOGG Wiki
In late 2015, the ISOGG YSNP Tree committee adopted some new guidelines that would disqualify mutations that did not meet some quality standards. These guidelines are somewhat arbitrary but necessary. The main problem is that the reports provided by software do not recognize items which are virtually duplicated in other parts of the chromosome (such as the X-duplication area between 2.9 and 6.5 million on the Y - Build 37 numbering) OR items that are in repetitive locations. The existing tree is being culled to remove items that do not meet these standards. It is a time-consuming process, and it is only complete for most of G and O presently. Also, we are allowing items with ^ symbols that do not meet these quality standards but are very helpful. The bulk of these are shared SNPs with fewer than 4 reads in next-generation sequencing in any sample submitted. The majority of these will turn out valid with better testing.