There are standardized whistles for high lead, slack line and tension skidders. I've a safety book with the whole list and you might be able to get it online although I'm not sure where. Might try searching WA Department of Labor and Industries.
That being said the last few years I worked every outfit seemed to have a bit different whistles for something. Not hard to learn after you knew the basics but you needed to ask on the first day.
A few from memory:
High Lead
Stop all lines:1 short
Ahead on the mainline: 3 short
Easy on mainline: 3 short and 3 short
Slack main: 4 short
Ahead on haulback: 2 short
Easy on haulback: 2 short 2 short
Slack haulback: 2 short 1 short or 2 short 4 short
Slack both lines: 1 medium long
Standing tightline when all stop: 1 short 2 short
Standing tightline in reverse while stopped: 1 short 2 short 2 short
Standing tightline while rigging coming back: 2 short
Running tightline while going ahead: 2 short
Take tightline off while continuing to go ahead: 2 short
Dump haulback while going ahead: 2 short 1 short
Resume haulback tension after dumping while continuing to go ahead: 2 short
Go ahead strawline: 3 short 1 short
Easy on strawline: 3 short 1 short 3 short
Slack strawline: 3 short 1 short 4 short
Then there are whistles for the chaser to send something from the landing, must be blown while rigging is on landing
Block and a strap: 1 short 1 long
Section of strawline strung out: 3 short 1 long every additional long whistle another section strung out
Section of strawline coiled: 3 short 1 short and every additional short another coil
To blow for chokers: 2 short and 1 short for every choker must be a space out, a long whistle at this time indicates a bull choker
Inspect the rigging: 1 short
Hooktender needed: 3 long
Man injured: 7 long
Quitting time: 1 long 1 short
Ahead on guyline: 2 short 2 short 2 short 1 short
Slack guyline: 2 short 2 short 2 short 4 short
Other whistles for various rigging made up by prior agreement but usually 1 long means send a saw
Slackline whistles, somethings stay the same but
Cable up on skyline: 2 short
Up easy on skyline: 1 short 2 short except when side blocking
Ahead on: skidding line: 3 short
Easy on skidding line: 3 short 3 short except when side blocking
Ahead on both: 2 short 3 short
You can blow 3 short while going ahead on both to make the engineer stop cabling the skyline or 2 short to pick up skyline while yarding turn
3 short to stop picking skyline and continue yarding
Slack skyline: 1 short
Fast slack on skyline: 1 medium long
Slack skidding line: 4 short
Ahead on haulback: 2 short 2 short
Easy on haulback: 2 short 2 short 2 short 2 short
Slack haulback: 2 short 1 short
When sideblocking to slack skyline while holding skidding line tight and going ahead on haulback: 2 short 2 short 2 short
Slacking skyline while holding haulback and going ahead on skidding line: 3 short 3 short
I'm probably forgetting some and maybe somewhat different whistles in other locales but that's what we used to use around here. All antique now as I doubt you'll see much high lead or slack line logging any more.