A symbol for hashtag: #.
The hashtag is used for quick filtering in Overview. With a combination of more hashtags, you can set up a more detailed filter for your records.
When you create or modify a record, the hashtag can be inserted into a note field by tapping on the icon (#) or by typing the symbol on your keyboard, and the expression that defines the hashtag follows.
If you use previously created hashtags, after typing the symbol a list of most frequently used hashtags appears.
Austria #holidays #fuel
Austria #holidays #food
Hashtags are also available for text search in filters.
At the present time, the app hasn't implemented a management of hashtags so they cannot be edited or deleted. However you can try this workaround solution to filter out all the record containing the hashtag and re-tag these records with a new tag. Unfortunately, the hashtag will still exist inside the app but no records will use it unless you use the hashtag again.