i have started an afghan. i am on row 2 and the instructions are as follows

ch5(counts as a dcand ch2 sp on this and following rows) dc in first dc*

can someone please break this down in english. i understand the rest of the directions, it's just this leading sentence that has me confused.

thanks i advance for your help

ch5 (counts as a dc and ch 2 sp on this and following rows) dc in first dc*

My interpretation:
if it a filet piece you're working on then:
you ch 5 and turn your work, make your dc in the next dc on the previous row.

If it's for increasing the row:
then you ch 5 (count as dc and ch2) and the instructions says dc in first dc which could mean: dc in the last dc of previous row where the ch 5 sts are made.
Hope this helps.
Hugs
Ferosa