Filter: Document FILTER_CALLBACK

[Girgias]

Remove the "Other filter" section

[kamil-tekiela]

Good, but what I think this page still lacks is the information about the callable signature. The example doesn't specify parameter type but makes assumption that it's always string. Is that true?

[Girgias]

Good, but what I think this page still lacks is the information about the callable signature. The example doesn't specify parameter type but makes assumption that it's always string. Is that true?

Yeah it is always a string: https://3v4l.org/J6k7r

[kamil-tekiela]

Good, but what I think this page still lacks is the information about the callable signature. The example doesn't specify parameter type but makes assumption that it's always string. Is that true?

Yeah it is always a string: https://3v4l.org/J6k7r

Good. Interesting that the last two didn't even trigger the callback.