Understand that ERC stands for Ethereum Request for Comments while EIP stands for Ethereum Improvement Proposal.
I refer to ERC20.
Are these request for comments (erc) translated to improvement proposals (eip) down the road?
The definition is in EIP-1
EIP stands for Ethereum Improvement Proposal. An EIP is a design document providing information to the Ethereum community, or describing a new feature for Ethereum or its processes or environment. The EIP should provide a concise technical specification of the feature and a rationale for the feature. The EIP author is responsible for building consensus within the community and documenting dissenting opinions.
ERC - application-level standards and conventions, including contract standards such as token standards (ERC20), name registries (ERC26, ERC137), URI schemes (ERC67), library/package formats (EIP82), and wallet formats (EIP75, EIP85).
The definition has mostly grown with the use. It was that an ERC is the original proposal, perhaps not complete, and with further input it is refined to something most participants will agree is useful and then it becomes an EIP.