Replace fragile quoted-implode station lists with normalized integer CSVs and where_in usage to ensure station_id lists are numeric. Add normalize_location_list helpers in multiple models (Lookup_model, Sig, Timeline_model) and update controllers to cast inputs (e.g. dxcc_id) to ints. Escape user-supplied SQL fragments with $this->db->escape_str/escape_like_str and sanitize band/mode parameters; consolidate band/mode filtering into add_band_mode_filters in Timeline_model. Add guards for empty location lists (returning empty results) and a method_exists check around a legacy vucc_shit call. Overall this improves input validation and reduces SQL injection risk while removing duplicated list-building logic.
Added server-side validation for callsign and station_id inputs in Oqrs controller to prevent invalid data and potential abuse. Updated Oqrs_model to use parameterized queries instead of string concatenation, improving security against SQL injection. Callsigns are now consistently uppercased before querying.