Here is a rule of thumb from this year's great energy debate:

The more important an issue is, from the standpoint of lowering oil consumption or increasing oil company profits, the less attention it tends to receive.

When President Carter unveiled his energy plan in April, it was his proposed standby gasoline tax that held center stage. But that direct tax on consumers, which Congress quickly killed, would have saved only about 350,000 barrels of oil a day by 1985, according to administration estimates.

The big oil-saver among the Carter proposed taxes was one to penalize industry for continuing use of oil and nautral gas instead of abundant coal. This, along with related coal measures, would have saved 2.2 million barrels a day in its original form, almost half the savings envisioned in the Carter program by 1985.

Yet the coal conversion tax, which the House approved in weakened form and the Senate has thus far rejected, has received only marginal public attention.

The same applies to Carter's assorted proposals for energy company profits.

There is, for example, a complicated set of regulations called the entitlements program that was set up to equalize the cost refiners pay for oil. It also subsidizes imports and means millions in profits for some companies. Carter's proposals would wipe this program out. Some companies want to preserve this piece of fine print, the public is scarcely aware of it.

The two things the companies care about most in the Carter plan - the price of natural gas and the price to producers of crude oil - are also often dependent on fine print.

The experts talk about things like old oil, new oil, plowbacks and decline rates. All of these have to do with price controls on oil - with moving oil out of low-price categories and into high-price ones.

One place where public attention and profits have merged is natural as pricing. Natural gas is the most prickly political issue in the energy bill facing Carter and a Congress divided on whether gas prices should be deregulated. Carter must preserve the aura of continuing gas price controls to claim a political victory.

The oil industry, on the other hand, is fighting for deregulation with near religious fervor. Gas is the one issue where the oil companies stand to make the largest increase in profits. Some oilmen say deregulation may end up a stalking horse, since the industry's central goal is to increase profits by getting the highest possible price for the largest volume of gas.

A 10-cent-a-barrel increase in the average price of U.S. oil results in $300 million in added annual income. A 10-cent per-thousand cubic feet increase in the average price of gas means $2 billion in new income. This would be an enormous jump in revenues, considering industry gas revenues at the wellhead totaled about $12 billion last year.

At the same time, despite a seven fold increase in new natural gas prices in the last five years - a jump of 445 per cent - the average price of natural gas under contract lags far behind oil prices. The average price of natural gas flowing in the U.S. today is about 65 cents per thousand cubic feet: the energy-equivalent price for oil would be $4 a barrel. Domestic oil on the other hand, is selling for an average price of $8.90 per barrel. Making up the difference, or even part of it will mean billions in new income, and an increase in profits.

Oilmen have wrestled an agreement in principle from Carter to support new gas prices at $2 per thousand cubic feet: Energy Secretary James R. Schlesinger Jr. said the administration would support a compromise $2.03 price offered by Sen. Henry Jackson (D-Wash.) Earlier the House passed Carter's proposed $1.75 price which is above the $1.47 price now in effect.

Summing up what the industry expects to win in the conference committee, David Foster who heads the Natural Gas Supply Committee, an industry group working for deregulation, says. "We have always been told that the administration is willing to go to higher prices to fight deregulation." Schlesinger's senior aides also say that the administration may have to go well over $2 to get controls extended to the now unregulated intrastate market.

With a price over $2 per thousand cubic feet nearly in hand, the industry will be working to give as much gas as possible covered by the higher price. "The thing now is not just the price of natural gas, but the definitions," says Lawrence Golstein of the Petroleum Research Foundation.

Carter proposed an arbitraby 2.5 mile, radius, 1,001 ft. depth boundary from producing reservoirs for gas to qualify for higher "new gas" prices. The House knocked this, out, leaving it essentially up to state authorities, while the Senate passed a more liberal definition allowing extensions of existing fields to qualify for new gas prices.Under the Senate plan, according to the Senate Energy Committee, 30 per cent more gas would be eligible for new gas prices, compared to what would qualify under the Carter plan.

Goldstein predicts, "The industry will not only see a higher price for new gas, but the amount of gas that qualifies for the higher price will be significant."

Just as the White House is out to preserve controls on natural gas. Carter must win approval for the crude oil equalization tax - which he has described as the "centerpiece" of his plan - to claim a political victory.

Under the House-passed bill, oil prices would be taxed up to the world price over a three-year period. The tax would raise $11.5 billion at full tilt, funds Carter wants returned to consumers. The tax would aslo end the entitlements program, which was set up to equalize the cost refiners pay for differently priced oil. In effect it provides a cash subsidy to oil companies for importing high cost foreign oil. There also is a special entitlements subsidy worth $100 million a month to so-called "mom and pop" small refiners, some of which are owned by Fortune 500 companies.

The Senate Finance Committee has rejected the crude tax.Instead it voted for a Christmas tree bill ladened with $40 billion in tax credits and other incentives targeted almost totally at new production which Chairman Russell B. Long (D-La.) says will produce 2.2 million barrels a day by 1985.

As in the case of natural gas, oil-men are in search of definitional changes and other legislative wording that would boost profits by reducing the amount of oil under price controls.

Ostensibly the oil industry is divided on the crude tax. Mobil Oil Corp., for example, is running advertisements against the tax and has linked arms in an improbably coalition with consumer and labor groups fighting the tax because they fear some of it will end up in the companies' pockets. Other companies such as Exxon have not spoken up against the tax.

At an Oct. 14 meeting with Schlesinger, howevr, Charles DiBona of the American Petroleum Institute said the industry, including independent oilmen, would support the crude oil tax in exchange for concessions on a list of measures that would lead to higher profits.

Asked about the meeting afterward, a senior Energy Department official said. "There is no deal with anybody."

The industry demands for supporting the crude tax include three key concessions, parts of which are already stitched into Long's Finance bill.

They would like a decline of 1.5 per cent per month in the amount of oil under price controls. Under one version of the "decline curve," they would like to receive a rebate on amount of crude tax paid equal to the value of oil freed from controls. This would especially benefit major oil companies who own large inventories of "old oil," selling for $5.25 a barrel A 1.5 per cent decline curve would decontrol half of old oil in three years.

Second, oilmen want a liberal definition of so-called "marginal properties" eligible for world oil prices.Currently oil from wells producing less than 10 barrels a day, called "stripper wells" is sold free of controls. The industry wants a broader definition written into the energy bill.

Finally, the oil companies will fight to eliminate the "composite price" mechanism enacted into law in 1975. Under the composite price regulations, oil prices have been rolled back or reduced under the government's complicated regulatory system. Schlesinger has said the administration eliminate the composite price, but the companies want it in writing.

In a sense, the largest unanswered question remaining in the energy debate raging on in the conference committee meeting is just that. How much will the oil companies be able to get in writing?