ISV Reliance of the Gateway Public API
HMRC provide software development support for government gateway interfaces
https://www.gov.uk/government/collections/government-gateway-support-for-software-developers

One of those interfaces is the Gateway Public API.  
https://www.gov.uk/government/publications/government-gateway-accessing-public-api-portal 

We're looking to check your reliance of the Gateway Public API and we'd like to understand your usage as an ISV and the effect this may have on you.

The API in question can be found at the following address:(https://secure.gateway.gov.uk/soap/2007/02/Public/Public.asmx)
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