The whole Common Procurement Vocabulary — all 9,454 codes, straight from the European Commission's own list — searchable by code or by what it means. 3,554 of them have tenders open right now; those link through to the contracts.
Every contract notice published in the EU Official Journal is tagged with codes from the Common Procurement Vocabulary, an eight-digit classification that says what is being bought, independently of the language it is bought in. It is the only reliable way to follow one kind of work across twenty-seven countries: a road resurfacing contract is 45233220 whether the notice is written in Portuguese, Estonian or Greek.
The digits narrow from left to right. The first two are the division — 45 is construction work. The third adds the group, the fourth the class, the fifth the category; the remaining digits refine further, and the final digit is a check digit. A buyer picks one main code and may add others.
Suppliers use them to filter: pick the codes that describe what you sell, and you can watch the whole single market instead of one national portal.