def session_to_viscode(session_name):
    """Replace the session label 'bl' with 'M00' or capitalize the session name passed as input.

    Args:
        session_name: MXX

    Returns:
        M00 if is the baseline session or the original session name capitalized
    """
    if session_name == "M00":
        return "bl"
    else:
        return session_name.lower()