RFA Java Level2 message indication of CLEAR_CACHE

As part of Level2 development our application caches and maintains the Level2 book in-memory. We noticed that sometime we get response with message indication of CLEAR_CACHE. Please clarify the following :

- Is CLEAR_CACHE only received by applications on REFRESH response or it can come as part of UPDATE response as well?

- What should we do when we receive CLEAR_CACHE indication,

1) should we clear our cache and consume the incoming message with CLEAR_CACH indication

OR

2) clear our cache and do not process the incoming message which has indication of CLEAR CACHE.