Is it possible to automate board annotation based on custom rules using Python in KiCad?
Automating board annotation based on custom rules is a powerful application of KiCad's Python scripting. Here's a conceptual script:

```python
import pcbnew

# Load the current board
board = pcbnew.GetBoard()

# Define your custom rules for annotation
# For example, annotating based on component type, location, etc.

# Iterate through footprints and apply custom annotations
for footprint in board.GetFootprints():
    # Apply your annotation logic here
    # For example, adding text labels or modifying footprint properties based on your rules

# Save the annotated board
board.Save('path/to/save/your/pcb.kicad_pcb')
```

This script would need specific logic based on your custom rules, potentially involving complex conditions and board modifications.