The phrase "a formal requirement" is correct and usable in written English.
It can be used when discussing rules, regulations, or criteria that must be met in a specific context, such as legal, academic, or professional settings.
Example: "Submitting a signed application form is a formal requirement for all candidates applying for the scholarship."
Alternatives: "an official requirement" or "a mandatory condition".
EQA and other methods of interlaboratory comparison are a formal requirement of ISO 15189, but are rarely required by legislation.
But Amazon's resistance to a formal requirement about diversity isn't unusual.
The second point worth mentioning is that Amazon's resistance to a formal requirement about diversity isn't unusual.
The 1980s saw the rhetoric of economic justification becoming a formal requirement for government subsidy for creative and cultural ventures.
Although conscription is a formal requirement, like most other Russians of my generation, I never served in the military.
Horizon 2020 funding is granted to consortia, not individual organisations, and there is a formal requirement that at least three countries must be involved in any given proposal.
A formal requirements specification language plays an important role in software development.
An important aspect of the architecture is the clear separation between monitoring implementation-dependent low-level behaviors and checking high-level behaviors against a formal requirements specification.
Design patterns guide the creation of a formal requirements document (the service guideline) which, in turn, can be translated into a technology-free consistent description (abstract service code) assisted by implementation patterns.
Condition (i) is indeed a rather obvious formal requirement.
The -196C>A, 1779T>G and 1822insT mutations were not observed in the SIRS patients, while the 1888insT mutation was observed in two SIRS patients and was therefore treated as a polymorphism, although not meeting the formal requirement of an allele frequency ≥ 1%.
