Linear tape open is a famous tape drive technology.

The LTO Consortium defines the new generations LTO-1, LTO-2... from time to time. It makes sense to merge all tags to lto, because the the version number does not name something completely different. It would be more useful to add a different tag to a question than to use lto and lto-4 for example.

Differences are mostly

• higher speed and larger cartridges for newer generations
• hardware encryption since LTO-4

But these differences are not critical to categorize the questions. The user will provide the required details (software, LTO generation...) in the question.