Salesforce Style Guide for Documentation and User Interface Text
j@Mention
An @mention is the @ symbol followed by the name of a person or group, for example, @Maria Sanchez or @DocTeam. @Mentions are used in Chatter posts and comments to tag people and groups. When you @mention a user or group, your post appears in their feed, and the @mention links to their profile.
Capitalization
Capitalize @mentionas you
would other words. Use uppercase if it’s the first word in a sentence or part of a title.
Otherwise, use lowercase.
Example
@Mention users when sharing a file with groups.
In the Comments field, @mention users and groups.
Context
You can use @Mention as a verb or
a noun, as well as in plural form.
Example
@Mentioned people receive email notifications of your post.
In your comment, @mention any users you want to notify.
The @mention links to the person’s profile.