Unclear description of Renewal Exemption and Duplicate Certificates

[Greek64]

@cpu I would like to continue our conversation from here until I understand how the rate limits work.
Then I will probably make a PR to address this issue.

To make sure you can always renew your certificates when you need to, we have a Renewal Exemption to the Certificates per Registered Domain limit.

This sentence is too ambiguous IMO, and suggests that I can always renew a certificate (i.e. no rate limit for renewals)

Even if you’ve hit the limit for the week,

Even if the limit this sentence refers to is probably the Certificates per Registered Domain limit mentioned in the previous sentence, it is still a bit vague saying the limit in a page that mentions several different limits.

This is the same definition used for the Duplicate Certificate limit described above. Renewals are still subject to the Duplicate Certificate limit.

So, correct me if I'm wrong, but the only difference between a Duplicate Certificate and a Renewal Certificate is that the Duplicate Certificates count against the Certificates per registered Domain limit in addition to their own Duplicate limit, but the Renewal Certificates count only towards the Duplicate limit.
In other words, you can have a Renewal Certificate (in the sense of this definition) only if you have hit the Certificates per registered Domain limit for that week.

If so, why even bother too differentiate them? This just makes things confusing.
Just state the definition of a renewal (same set of hostnames), the renewal limit (5 per week), and that the renewals are counted against the Certificates per registered Domain limit, BUT are not limited by it.

[jsha]

There no difference between Duplicate certificates and Renewal certificates. I'm definitely open to amending the language for clarity. Maybe it makes sense to first define "Renewal," and say there is both a Renewal Exemption to the per-domain limit, and an independent limit on Renewals?