All the term attributes (except the first comment) can be edited in the Terms page.
Each term (text/string to be translated) in POEditor can have the following attributes.
In POEditor, the uniqueness of a term is based on the context it has. If you change the context of a term, you end up with a different term, even if the text to be translated is the same. Except for the case of Gettext .po and .pot files, there aren't general rules regarding how to use it.
To avoid ending up with duplicate terms, we recommend you place any observations that you'd like to share with your translators in the comments.
The Reference attribute is file-specific. You'll find it most often in Gettext language files. but .xls, .csv and the .json we use for transport with the API can support it too. Usually, it comes from the file, on import.
There aren't general rules regarding how to use it, except for Gettext file formats. In .po and .pot files, it's where you put the paths to the files where the string can be found.
You can import plurals from your file or enable them manually in the Terms page. The plural forms for each term are set automatically once they are enabled, according to each language, following this list. Not all file formats supported by POEditor support plurals, just the ones listed here.
The first comment
Not exactly a term attribute but acting like one is the first comment of each term. It is preserved during export/import, so if you some information that you want to preserve during the entire localization process (such as links to screenshots), you might want to put them in the first comment.
The terms in POEditor are project-wide. This means that they are counted only once that and any change made to a term will be reflected in all the languages.