Explain when and where comma, whitespace, etc. are ignored

### Description

> A brief description of the Documentation Improvement or New Section request.

I am currently scanning a file with the following license reference:

```
Licensed under GPLv2, see file LICENSE in this source tree.
```

scancode reports a match for rule `gpl-2.0_147.RULE` which has the following:

```
Licensed under GPLv2.
```

The file I am scanning has a comma, while the rule has a dot, yet it matches. This makes me wonder if scancode first preprocesses data and ignores commas, whitespace, and others, and if so: when (at the end of a sentence? mid-sentence?). This could possibly be relevant when writing license rules.

### Link to Documentation Page

> Where the confusion/inconsistency/incomplete documentation is.

### Select Category

- [ ] Inconsistency
- [ ] New Section Request
- [ ] General Improvement
- [ ] Typo/Mistakes
- [X] Other