Subtraction in binary code is performed similarly to decimal subtraction, using the rules of subtraction with binary values. Here are the steps for binary subtraction:

1. Preparation:
   - Ensure that the numbers have the same number of digits. If not, pad the numbers with zeros on the left to make them equal.

2. Subtraction by Digits:
   - Start from the rightmost digit and move to the left.
   - Subtract each bit of one number from the corresponding bit of the other number.
   - If the result is negative, borrow "1" from the higher-order bit.

3. Borrow:
   - If the subtracted bit is greater than the subtracting bit, borrow "1" from the next higher-order bit and add it to the subtracting bit.

4. Result:
   - The result is represented in binary form.

Let's consider an example of binary subtraction:
Example: 1011 - 0101

```
      1 0 1 1    (Minuend)
  -     0 1 0 1    (Subtrahend)
  ______________
      1 0 0 0    (Result)
```

In this example, starting from the rightmost digit, we subtract each bit. If the subtracted bit is greater than the corresponding bit in the minuend, we borrow "1" from the next higher-order bit. The result of subtracting 1011 - 0101 is 1000 in binary.

This is the basic process of binary subtraction. I hope this helps!