The phrase "a basic rule is that" is correct and usable in written English.
You can use it to introduce a fundamental principle or guideline that is generally accepted in a particular context.
Example: "A basic rule is that all team members should communicate openly to ensure effective collaboration."
Alternatives: "a fundamental principle is that" or "a key guideline is that".
Moreover, a basic rule was that policy implications should be clearly spelt out.
A basic rule is to choose a boat that accommodates two more than are in your party; that way you won't have to convert the dinette to a double bed.
Ms. Hallenborg noted that while the initial registration forms will probably not include services added after the forms were filed, the basic rule is that any service a regulated tenant had at the inception of the tenancy — or any provided thereafter and included in the rent — is considered a base-date service.
"The basic rule is that any development on a beach or dune or within 150 feet of the mean high water line of a tidal water body in New Jersey must meet the requirements of the state's Coastal Area Facility Review Act," Mr. LaMonica said.
Every other civilised country in the world taxes its inhabitants on their income and capital: the basic rule is that if you live in a place, you pay its taxes.
The basic rule is that the tea is steeped in a warmed pot for 20 to 45 seconds, allowing the leaves to unfurl.
58 Taking this into account and since the basic rule is that all oedemas result from an imbalance between filtration and resorption (tissue drainage), the implementation of a measure to restore this balance during the period of higher filtration should prevent or delay the onset of secondary lymphoedema.
So, there's two systematic methods, and let's say the basic rule is that you should give both of them a chance.
The basic rule is that if we have the probability amplitude for a given complex process involving more than one electron, then when we include (as we always must) the complementary Feynman diagram in which we just exchange two electron events, the resulting amplitude is the reverse – the negative – of the first.
