def owl_or_skos(label_safe, prefixes):
    """
    Build a generic RDF import substring.

    Parameters
    ----------
    label_safe : string
        URI

    prefixes : dictionary
        dictionary {string : string} of prefix keys and
        conceptualization values

    Returns
    -------
    conceptualisation : string
        "OWL" or "SKOS", default "OWL"

    """
    return (prefixes[label_safe.split(":")[0]] if (
        ":" in label_safe and
        "//" not in label_safe and
        not label_safe.startswith(":") and
        label_safe.split(":")[0] in prefixes
        ) else "OWL")