In picard/ui/cdlookup.py and isrcsubmitdialog.py, format_isrc() is used to format ISRCs for display.
Currently, if raw metadata or CD reads provide valid ISRCs in lowercase (e.g. "usrc17607839") or without hyphens, format_isrc() skips formatting because _ISRC_RE strictly expects uppercase [A-Z], leaving them unformatted instead of displaying as "US-RC1-76-07839".
 
Expected behavior:
Valid ISRCs should be normalized (uppercased and stripped of hyphens/spaces) before validation and canonical hyphenation so any valid ISRC is consistently displayed in standard format (CC-XXX-YY-NNNNN).
 
PR: https://github.com/metabrainz/picard/pull/3532