IPLD (Interplanetary Linked Data)
IPLD is the data model of the content-addressable web. It allows us to treat all hash-linked data structures as subsets of a unified information space, unifying all data models that link data with hashes as instances of IPLD.
WHY IPLD?

A data model for interoperable protocols.Content addressing through hashes has become a widely-used means of connecting data in distributed systems, from the blockchains that run your favorite cryptocurrencies, to the commits that back your code, to the web’s content at large. Yet, whilst all of these tools rely on some common primitives, their specific underlying data structures are not interoperable.
Enter IPLD: IPLD is a single namespace for all hash-inspired protocols. Through IPLD, links can be traversed across protocols, allowing you explore data regardless of the underlying protocol.
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The webpage is annoyingly vague so you will need to visit the IPLD spec Github page and consider this whitepaper: IPFS – Content Addressed, Versioned, P2P File System (DRAFT 3) by Juan Benet.
As you read, can annotation of “links” avoid confusing of addresses with identifiers?
We’ve seen that before and the inability to acknowledge/correct the mistake was deadly.