A company that repairs industrial equipment might also sell replacement parts. A distributor may do installation work as well. Both can appear under more than one industry label, and the label alone won't tell a buyer which part of the business matters to the deal.
For a first screen, start with the company's work and its customers. The U. S. Census Bureau says the North American Industry Classification System (NAICS) is used by federal statistical agencies to classify business establishments for economic data. That makes the label useful for organizing a search. It does not answer whether a company fits a particular investment plan. Read the Census Bureau's NAICS overview.
Find the main line of business
Ask what customers pay the company to do. Look at its service list, product catalog, public descriptions, and, when available, a revenue breakdown by business line. A business may offer several things, but one activity may account for most of its sales or explain why customers choose it.
Take the equipment example. The first screen should show how much revenue comes from repair work and how much from parts, if those figures are available. If the materials are not clear, note that as an open question. Don't choose whichever label sounds closest and treat it as a conclusion.
Look at who buys and what they need
The same service can mean different things in different markets. A contractor serving factories may face different customer needs from one working mainly in homes. A software provider may sell to hospitals, manufacturers, or professional-services firms. The customer base and end market can help explain what the company really does.
At the first-screen stage, use facts that are already available: customer types, end markets, locations served, and the split between repeat work and one-time projects. If an important detail is missing, record the specific question. A label should not stand in for information the buyer still needs.
Compare the facts with the investment plan
Once the business is clear, compare it with the firm's actual acquisition criteria. Does its main activity fit the sector focus? Do its size, geography, ownership, and transaction profile fit too? Could the company work as a platform, or does its value depend on adding it to an existing business? Those are separate questions from whether it touches a sector the firm follows.
A company may fit one part of the mandate and miss another. Keep both facts visible. Don't broaden the buy box just because a company's secondary service overlaps with the thesis; that can turn a specific screen into a list of businesses with little in common.
Write down what is known and what is not
A short note is enough for a first review: the company's main activity, the customer or end market, the facts that support a possible fit, and one question that could change the screen. If the available information supports a clear pass, say why. If one answer could move the company forward, ask for that answer before requesting a full package.
When a business sits between sectors, the buyer does not need a perfect label to make a useful first decision. Follow the revenue, the customers, and the mandate. That gives the team a clearer reason to continue, pause, or pass.