When selecting the search criteria for your daily tender notifications you will be asked to select the categories relevant to the types of tenders that you are interested in.
Only select the categories relating to the goods and/or services that you can provide and not the industries that you can provide them to. In most cases you should only need to select a few categories.
Each category selected will increase the number of opportunities you receive and selecting too many categories will make it easy for you to overlook an interesting opportunity in amongst all the irrelevant results.