I have been testing out the drupal Merge module to clean-up taxonomy terms. This module is helpful if you have similar terms (like inch and inches or pounds and lbs) that you would like to merge. The module allows you to keep the term you prefer and replace the other terms with the preferred term, and updates all logs to reference the preferred term.
Here are some successful merges that I have tested using the module:
- Merge seeds into Seeds(s) in unit taxonomy terms
- Merging lb, lbs., lbs, into lbs in unit taxonomy terms
- Merge corns, field corn and flint corn into corn in plant type taxonomy terms
- Merge angus and angus red into red angus in animal type taxonomy terms
- Merge child terms into parent terms in unit taxonomy terms
The only time I encountered an error was when trying to merge a term that is a parent of another taxonomy term. You can merge child terms into parent terms (making the parent the preferred term) but you cannot merge a parent term into another term, this is blocked because of the relationship with the child term.