def parse_crs_string(string: str) -> str:
    """Parses a string to determine the CRS/spatial projection format.

    Args:
        string: a string with CRS/projection data.

    Returns:
        crs_type: Str in ["wkt", "proj4", "epsg", "string"].
    """
    if "epsg:" in string.lower():
        return "epsg"
    elif "+proj" in string:
        return "proj4"
    elif "SPHEROID" in string:
        return "wkt"
    else:
        return "string"