Constant VALID_ROOMS 

const VALID_ROOMS: &[i16];

A hardcoded list of valid room numbers for ticket submissions.

This array contains i16 values representing valid rooms. Negative numbers typically denote rooms prefixed with ‘K’ (e.g., -1 for K1), and numbers greater than or equal to 1000 denote rooms prefixed with ‘D’ (e.g., 1001 for D1).

This list is used for client-side validation of room input during ticket creation.