At left is a view of the out-of-the-box invalid serial number table. Looking at the serial number table (Discovery → Serial Numbers) for the Wooden Spaceship here, I see that we have a serial number "Not Available" showing up as a valid serial number — and clearly, it is not valid. I'll use this as a real-world example of how to make a new entry in the invalid serial numbers to take care of this.
- Type: This field controls what kind of comparison is done against the serial field. I chose Is because I want to eliminate serial numbers that exactly match "Not Available". There are two other choices: Contains, which will match the serial field if it appears anywhere in a serial number, and Matches Regular Expression, which is a powerful matching tool if you happen to know regular expresssions.
- Serial: This field is what you're testing against serial numbers Discovery reads from your equipment. Discovery does two things before it does the actual comparison. First it removes any ignore characters (see the Ignore field below) from both the Serial field and the serial number being tested. In our case, that means the Serial field becomes "notavailable" before comparison, because a space is one of the ignore characters. Second, if the Case sensitive field is not checked, it converts both the Serial field and the serial number being tested to all lower-case characters. After these two steps, Discovery does the comparison you specified in the Type field.
- Case sensitive: If checked, then comparisons will only match if the case of the characters matches — "A" matches "A", but not "a". If unchecked, then the case of a character doesn't matter. More here.
- Ignore: This field specifies a list of characters that will be ignored in any comparison. See the Serial field for details on how this works.
