# Find and explain an extra space

Inspect the raw difference and keep exact mismatch separate from a configured match.

Source: https://help.smartfact.ai/scannerbench/guides/extra-space

Audience: Operator

## Find and explain an extra space

1. **Start capture in the focused box**

   Start capture in the focused box.

   Start capture explicitly. Only this box collects keyboard input. These keystrokes are simulated; the course does not measure a physical scanner.

2. **Scan a value with an extra space**

   Scan a value with an extra space.

   This prepared input has one trailing ASCII space. Read the escaped text instead of judging by the visible barcode or number.

3. **Keep the independent expectation exact**

   Keep the independent expectation exact.

   The known encoded value has no trailing space. An exact mismatch identifies a real difference; it must not be hidden by automatic trimming.

4. **Name the invisible characters**

   Name the invisible characters.

   The inspector shows Unicode names and code points. It helps distinguish spaces and controls that an ordinary text view can hide.

5. **Open explicit comparison rules**

   Open explicit comparison rules.

   Rules transform received text in order. The original capture and exact comparison remain visible. They do not reprogram the scanner.

6. **Add an explicit space-trimming rule**

   Add an explicit space-trimming rule.

   Configured match is a separate result. The raw trailing space and exact mismatch remain evidence of what arrived.

[Watch or practise this chapter](https://help.smartfact.ai/scannerbench/demo?guide=extra-space&chapter=extra-space)