Inventory Filtering

The inventory filtering endpoint filters for bonds that are available
for trading at the time of the request. Multiple fields can be filtered
for, including reference data fields (such as S&P rating, bond type) as
well as the bid / ask price and yields. These filters should be
specified in the filters field. We're also able to filter for ISINs
that fulfil a specific trade size.

Two types of filtering are supported:

• Reference data filtering: specify filters for reference data fields,
  such as S&P rating, bond type, and more.
• Live inventory filtering: specify filters for price, yield to
  maturity, and yield to worst, filter for quotes that match a trade
  size, and get bids and asks from the returns field.

In addition, specific fields can be requested in the response. These
fields should be specified in the returns field.