integrity-like property

Hi all,
I was reading "Verifiable Credentials Data Model 1.0". The Data schema part (https://www.w3.org/TR/vc-data-model/#data-schemas) specifies two properties: the id, and the type. IMHO it would have been really useful to have a third (optional) property similar to the "sub-resource integrity" tag used in HTML (https://developer.mozilla.org/en-US/docs/Web/Security/Subresource_Integrity). What is your opinion? Is there any other way to provide some integrity information about external resources in the VC data model?

Best,
Nikos