F5 Rule

Subscriptions are bought per number of instances on 1-, 2- or 3-year terms

Catalog row in Vendor License Rules · Cited

Kind: Entitlement
Statement: F5 purchasing page: subscriptions are sized by instance count for one to three years and include maintenance and support for version updates. (page undated)
Applies when: Buying a subscription
Applies to: F5 software subscriptions
Related programs: Term Subscription

Evidence 1

"Specify the number of instances you need and sign up for a 1-, 2-, or 3-year term."