Meaning of "tap once over"?

[color=blue]Could you please help me with the meaning of bold words below:

Bone-in Chicken Frying – 9pc / 11 min
Battered chicken
Wire basket
Chicken wire rack
Quality control bar
Food Safety
Gas fryer:340ºF (171ºC)
Electric fryer:
330ºF (165ºC)
165ºF (74ºC) [after draining]
160ºF (71ºC) [holding area]
Use correct fryer [spicy or mild]
Rotate fryer usage.
If any temperature reading
is out of range, contact manager.
1 Tap once over bus pan.
Skim into fryer from back to front:
Legs—right side
Thighs―center, cup side down
Keel Breasts―left side, cup side down
Rib Breast―cup side down
Wings― distribute evenly [by tips]
2 Press 11 minute timer.
Use wire basket to gently turn chicken at timer [after 6 minutes] from corners to center of fryer.
3 At timer, use wire basket to remove chicken and drain for 10 seconds.
Place chicken in chicken wire rack and drain for 60 seconds over shortening.
Hold Time
30 minutes
4 Use tongs to stack chicken as follows: legs, thighs, wings, ribs and keel breasts [thighs & breasts cup-side down].
Place in holding area―use quality control bar to indicate hold time.
Skim fryer after every drop.
5 After draining for
1 min 10 sec. take temperature in 2 places on 2 chicken breasts.
Minimum internal temperature must be 165ºF (74ºC).
Record in HACCP log.
Contact manager if any piece is below 165ºF (74ºC).
Move chicken to holding area.
6 Take temperature
in 2 places on 2 breasts in holding area.
Minimum internal temperature must be 160ºF (71ºC).
Record in HACCP log.
Contact manager if any piece is below 160ºF (71ºC).
Thanks very much!!!

I see that nobody has replied yet.
The instructions are written in shorthand which makes it ever so difficult to guess what it all means.
However you can find out the meanings of “gas/electic fryer” by googling them:

By the way, I’m surprised that you only find the bold parts unclear and the rest apparently doesn’t make you confused. To me it all looks pretty darn confusing at first blush.

Thanks for your help. After extensive Google search, I finally understand them all. It’s very nice of you. I really appreciate it.