Is it okay to keep the LOR neutral without specifying the specialty?

So here a question raised by those who would like to apply to backup programs or multiple specialties using the same LOR from the same writer: Is it okay to keep the LOR neutral without specifying the specialty?

The answer is Yes you can use a LOR that don't recommend you to a specific specialty but to residency in general to apply to multiple domains. You need to tell your letter of recommendation writer not to mention which residency specialty you are applying to, but instead, ask the writer to recommend you to residency in general.

For example, the writer can say I recommend Dr. xyz for your residency program instead of saying I recommend Dr. xyz for internal medicine residency. This way by hiding your future plans will give you more room to roam around various residencies with your application.