```ruby
# this feature flag gets overridden on deploy
ENABLE_WORDS_TO_AVOID_HIGHLIGHTING = !Rails.env.production?
```

Configure admin UI using HIGHLIGHT_WORDS_TO_AVOID env var
user
```ruby
if ENV.has_key?("HIGHLIGHT_WORDS_TO_AVOID")
  enabled = "true" == ENV["HIGHLIGHT_WORDS_TO_AVOID"]
else
  enabled = !Rails.env.production?
end

# Typically this isn't enabled in production
# It is primarily used as a training feature.
ENABLE_WORDS_TO_AVOID_HIGHLIGHTING = enabled
```
assistant