4.2.2.2.5 Classifying a Combination of Technical Subjects

Also in this Chapter:

• 4.2.2.2.1 Common Rule
• 4.2.2.2.2 First Place Priority Rule

• 4.2.2.2.3 Last Place Priority Rule

• 4.2.2.2.4 Special Rules​​​​​​​

In some subclasses, different general classification rules are used in different parts. For example, if only one main group in a scheme uses the last place priority rule and the other main groups use the common rule, the main group is selected using the common rule and a subgroup is selected according to the rule applied within the relevant main group.

It is important to remember that the general rules share the following essential features:

a) many technical subjects are completely covered by only one group in the subclass scheme; in this situation, the subject is classified in that group regardless of the general classification rule used in the subclass;

b) if two or more subjects of the invention are disclosed in the patent document, the general rule used in the subclass is separately applied for classifying each subject;

c) if a sub-combination of the subject of the invention is novel and non-obvious itself, it is separately classified according to the general rule used in the subclass.

It is only in situations where the technical subject is covered by two or more of groups of the subclass (i.e. some groups have potentially overlapping scope or groups are only available for sub-combinations of the subject and not for the subject itself) that the general classification rule used in the subclass is important for determining a relevant group or groups.