Understanding Armholes!

Hi, I am folliwing a pattern on a hooded cardigan and am a little confused by the shaping of the armholes! the patterns says cast off 3 sts at beg of next 2 rows (91)sts. Dec 1st at each end of next rows, then on 5 foll 4th rows, then on every foll alt row until 33sts rem.
Now Im fine with the first bit and the last bit but am confused about (then on 5 foll 4th rows) i dont unerstand what its asking me to do here please could someone explain. Thanks

After the BOs on 2 rows, you dec at the beg and end of the next row. Then dec again on the 4th row after that, for 5 times. In knitting ‘foll’ means ‘after’.