Help with leverage question

This is from rules for trader:

Trader not allowed to leverage more than 10 times on any one currency pair at any one time.
10 times Leverage would mean 10 Lots per currency pair on $10.000.00 or 12 Lots on $12.000.00 account or 20 lots max per currency pair on a $20.000.00 account. Of course you can work with less leverage as well, it does not have to be the limit on each and every trade.
Is this clear? ( anther way to think of it is 1 lot per $1000.00 in the account per currency pair)

I'm confused. Here is rules for handling leverage. How lots is calculated here? Ok. My thoughts. 1 lot =100 000 usd.
I understand that here maximum leverage would be 1:10. So if I have 10 000 usd deposit, I can open 10 lots? How is that calculated?
Or that is forexfactory trade explorers leverage formula?

Leverage depends on margin. There is formula how to find the margin:

Margin = lot*size contract/leverage

The leverage is relation of equity to borrowed funds. So if you have equity 10 000 usd, yyou can't open any lot. because 1 lot=100 000 usd. You need 90 000 usd to buy 1 lot, yes? so, now we do next: 90 000 usd/ 10 000 = 9. So the leverage to buy 1 lot if you equity is 10 000usd, will be 1:9. but many brokers doesn't have the leverage 1:9, they have 1:10, so your leverage proceeding from your equity will be 1:10. It'll be your optimal leverage, your practical leverage.

I understand this process in this way. If I'm not right, please, correct me!!!

I don't know what rules you are quoting from
I lot is NOT necessarily $100,000
On currency pairs where USD is quoted first, then yes, it is $100,000, ie USDJPY, USDCAD
But for example GBPUSD, 1 lot is 100,000 GBP, currently about $152,000
So with a $10,000 account with 10:1 leverage, you would not be able to open 1 lot on GBPUSD, you would only be able to open 0.6 lot