In German language there is a phrase called "Schubladendenken". It refers to putting a thing into a box and all its entities are framed only by that box. In general this way of thinking is considered as bad or narrowed. A lot of self-proclaimed coaches instead of actually helping, talk about such wise phrases like "Think out of the box". Nevertheless, framing things within a certain boundary or mathematically expressed by modelling it, helps to understand concepts. It helps to give a basic idea that probably only matches 80 to 90 percent of the actual thing, covering all its individual properties and details by the rest. Similar like creating an AI, that works quite well for 80 percent of the use cases, but fails when it comes to the 20 percent detail. Nevertheless, the concept of the AI is explainable by those 80 percent.
Law is the description of how people want to interact. As it treats people, there is a subjective part that might fall into the 20 percentage that is not formally defined and part of law interpretation. The other 80 percent are approached by formal definition of law. When it comes to Intellecutal Property (IP), as some little aspect of law, it comes to register immaterial legal assets. Those assets are introduced into a register. It is the legal term for an official recognization by the state with all its duties and rights. A register, from a technical perspective, is a database. Trademarks as some form of IP, are listed in such a register for example in Germany. A TM contains a lot of subjective and ideology part. All those elements that an individum connects with a brand and finally convinces it to buy it. Nevertheless, it has some basic properties, that can be measured and formally described. Therefore, considered a structured format for those Trademark (TM) register entries, any classification column reflects the idea of narrowing an entry down to some sort of box. For TMs, this IP classification is called Nice classification. Nice is a town in the south of France where in 1957 this international agreement has been signed and later ratified by its member states. This treaty has been moderated by the World Intellectual Property Organization (WIPO). It still holds the administration of it, meaning, any changes or adoptions are intermediated by them to the signing states. It basically says, that any state that signs this treaty will employ the classifications of Goods and Services defined, to all Trademarks in their register. It is an approach to harmonize IP law on international level. Each IP office has to includes this classification to their official documentation of Trademarks. It serves as a frame for the use and validity of the mark. Different frames in each legal territory could cause economical instability as Trademark holders would probably face more legal conflicts due to different interpretations in each classfication scheme. There are 34 classes for Goods defined and 10 classes for Services, each in alphabetical order.
When it comes to engineering all classes can be involved somehow. But when it is all about coding and software, some specific classes are of higher relevance than others. Docker is a famous virtualization software to run applications in a loosely coupled environment called a container. The term Docker refers not only to that, but also to their Docker Hub, Docker CLI Docker images, Docker Scout or Docker Swarm. It is an open software to use for anybody, but on industrial scale, they offer some advanced services. A model in the software world called "Freemium". So Docker Inc. has some IP and reason to protect it. By using EUIPO's TMView to search for "Docker" leads to 8 register entries. "Docker" refers not just to software, that is why the database filters "holder=Docker Inc. AND status=registered AND offices=EUIPO" are selected. In the "Goods and Services" column, there are only 2 different classes visible. Number 9 and number 42 which stand for "... Recorded and downloadable media, computer software, blank digital or analogue recording and storage media; ..." and "... Design and development of computer hardware and software" correspondingly.
Another famous software product is "Java". It refers to the programming language but for example also to the Compiler. When filtering TMView again with "holder=Oracle Inc. AND office=EUIPO AND status=registered", 17 items appear. Eight of them have class 42, 11 have class 9 on their registry entry. But Oracle Inc. registered their Java related intellectual property items with more classes, namely: 16: "Paper and cardboard; Printed matter; Bookbinding material; Photographs; Stationery and office requisites, except furniture; Adhesives for stationery or household purposes; Drawing materials and materials for artists; Paintbrushes; Instructional and teaching materials; Plastic sheets, films and bags for wrapping and packaging; Printers' type, printing blocks", 35: "Advertising; Business management, organization and administration; Office functions", 37: "Construction services; Installation and repair services; Mining extraction, oil and gas drilling", 38: "Telecommunications services", 41: "Education; Providing of training; ...", and 45: "Legal services; Security services for the physical protection of tangible property and individuals; Personal and social services rendered by others to meet the needs of individuals"
For a software developer mainly the Nice classes 9, 38, 41 and 42 should be kept in mind.