Page History

...

Work around is to collapse  the Activity tab when having more then 10 comments to add a new comment.
Please note that settings are saved when you collapse a section, when opening a new Jira issue make sure you have opened the section again.

Mentions (tagging)

Mentions (often known as @mentions) are a useful way of drawing someone's attention to a issue or a comment.
When you mention a user, they'll receive a notification by email.

You could also reassign a issue to a colleague for consultation, but that’s a fairly heavyweight operation to just ask a question.
By using @mentions, you can quickly direct conversation in comments to get needed feedback and keep you moving forward.
That way the issue always stays assigned to you and on your radar.

The following users can being mentioned in Jira:

• Reporter
• Commenter 
• Asignee
• Licensed users: YMEUACJiraServiceDeskUsers / YMEUACJiraYMEPAServicedeskUsers

...

• (Jira Servicedesk)  YMEUACJiraUsers (Jira Software)

Requested participants of a

...

issue which are only Jira Servicedesk portal customers cannot being mentioned, unless they have left a comment in the ticket, then they will  become a commenter on

...

the issue.

User mention via comment using autocomplete

To mention someone using autocomplete, type '@' in the editor then start typing their name. Choose the person you want to mention from the list of suggestions. 

Jira will suggest people you've mentioned previously (after yourself, of course).

Image Added

It then continues to suggest matches as you type. If you've not mentioned the person recently, we'll also include information about whether they've commented or contributed to the current page, to help you find the right person, fast.
Image Added

Select the person you want to mention and it will be added to the issue comment box.

Image Added

User Mention via editor in the toolbar

If you'd rather use the Insert menu, choose Insert > User Mention then search for and select the user you want to mention.

Image Added
Image Added

Image Added

Jira mentions dashboard filter

Following filter can being used in your dashboard to display all unresolved tickets of the last 7 days where you have being mentioned in.

• All Issues I’m mentioned in 

Workflow

A Jira Workflow has three basic components: statuses, transitions and resolutions.

...

• The "Hide completed issues older than" is easiest to use, but allows limited values.
• The "Kanban board sub-filter" can be used with any query imaginable. The one in the example allows limiting to items X days old.

Image Modified

Board Quick Filters

At the top of a team board you usually find Quick Filters. These are specifically designed for your team board.

...