[wazanator]

A phone number is already 10 digits. As long as you put proper break characters between the groupings it's not hard to read IMO.

[govg]

They could also just generate 4 words and string them together as the password. Considerably more entropy than 10 digital and easier to communicate too.

[PeterisP]

You need the ability to enter the code on a numeric keypad when dialing in from an office phone. Compatibility with "ancient" enterprise practices is also important.

[fart_ratty]

Using american-english dictionary from aspell [1] and filtering for lines that only contain lower case letters [2] gives you 77649 words. For four words that gives approx 64 bits of entropy [3].

[1] Probably available on a Linux system at /usr/share/dict/american-english

[2] '^[a-z]+$'

[3] log_2(77649^4)

[jimmySixDOF]

Kind of like the what3words approach to GIS

[1] https://what3words.com/about-us/

[noodlesUK]

This is exactly what jitsi does

[adtac]

English-specific tho