Subject: does cutoff value for 16S rDNA match is same for full and short sequences

similarity match cutoff for 16s rRNA gene for identification of bacteria used
are less than 99% for new specie and less than 97% for new genus.do these cut
offs apply equally to both full length sequences and shorter sequences as well?,
usually 400-500bp length sequences are documented that target either variable
region 3 or variable region 6 or other..does the full length sequence %identity
will be different from shorter length sequences? 

Re: does cutoff value for 16S rDNA match is same for full and short sequences