cdm/src/main/java/ucar/nc2/util/rc/RC.java
static synchronized public String
  find(String key, String url) {
    if (key == null) return null;
    if (!initialized) RC.initialize();
    Triple t = dfaltRC.lookup(key, url);
    return (t == null ? null : t.value);
  }
static synchronized public String
  find(String key, String url) {
    if (key == null) return null;
    if (!initialized) RC.initialize();
    Triple t = dfaltRC.lookup(key, url);
    return (t == null ? null : t.value);
  }
Allow users to search the default rc

@param key
@param url null => not url specific
@return value corresponding to key+url, or null if does not exist