Pure Entries are designated by the MDElement.LEVEL enumeration and are indexed by price. For a snapshot update, there can be zero or more Pure Entries. A snapshot with no Pure Entries is an empty snapshot showing an empty order book.

For incremental updates, there must be at least one Pure Entry. The price field is always a valid numerical value, and the amount field is always a non-zero positive number. (Negative amounts are invalid. Zero amounts are valid for Pure Entries being deleted).

For a given MarketView, there will be only one update per price level and side. You should not see multiple update actions (NEW/CHANGE/DELETE) on the same price level. It is recommended that the marketdata entries be processed in the order received messages. There is no guarantee on the order of the various side (BID/OFR) or update action (NEW/CHANGE/DELETE) as they appear in the sequence of market data entries.

Below is the only pure entry-type:

• MDElement.LEVEL - A (price, size) book level. Each price level has an amount which represents the liquidity available at the specified price. There are typically many of these entries for each side. This entry is used for exchanges which provide pure books, as well as for the L1 and L2 books as provided by EBS Ai with their 'DEALABLE' and 'DEALABLE PLUS' entries. These are also used for EBS Live L3 'ORDERBOOK' entries. These entries are assumed to be credit-screened.