Working with hundreds of translation labels for dozens of different website components (e.g. search, forms, settings, notifications, etc.) requires a certain amount of housekeeping.
Thus, structuring your dictionary entries into appropriate folders is always a good idea!
Two things matter here:
- the dictionary entry is contextualized by applying a use-case oriented folder structure (/Modules/Direct Links/...)
- the key of the dictionary entry resembles the actual item path, allowing a developer to easily find a given dictionary entry
And that's all you need to know about structuring Sitecore's dictionary entries.