In the 'Logback Filters' section of chapter 6, the second sentence of the first paragraph states:

"It the event's level is equal to the configured level, the filter accepts of denies the event, depending on its configuration."

I think that sentence has a couple of typos in it:

• 'It' should be 'If'
• 'of' should be 'or'

So I think the sentence should be:

"If the event's level is equal to the configured level, the filter accepts or denies the event, depending on its configuration."