The clearing process or component clearing means the process in which we identify the license under which the software component is licensed. This can be done using some license scanner, which scan the source code using different pattern matching algorithms to recognize the license text or parts of it.
Finding license related test from the source code is not so simple task, because of several reasons: there can be only parts of the full license text, license text can be slightly modified or there can be only a reference to see URL or some file. Also, when scanning a whole software project, it is obvious that there will be several different open source licenses in it, so it must also be taken into the consideration that the licenses are mutually compatible. The component clearing is not so straight forward process, so that is why there should be own team to do it.
It should also be distinguished that component clearing and license clearing are two different things. License clearing means the process where license text is read, and the granted rights, obligations and restrictions are evaluated for each license. License clearing is done at least with the help from legal and often by legal only.