Symbol protection is a filter that blocks users from using to many symbols in a message
This setting refers to how many symbol characters are allowed in a message
This setting refers to how many characters are need in order to check for maximum amount and maximum percentage, for instance if this setting is set to 10, the message
ⒶⓅⓇⓛⓁ ⒷⓄⓉ will not trigger the filter, instead
ⒶⓅⓇⓛⓁ ⒷⓄⓉ ⓛⓈ ⒼⓇⒺⒶⓉ will trigger the filter because it has a minimum of 10 characters and it has above 70% of symbols in the message.
This setting refers to how much percentage is allowed in a message, remember that this setting check the message only if the minimum characters setting is met, the formula for this filter is
symbol count /
message length checked against the percentage allowed