If your league has the Match Review feature enabled, the team captains and match umpires will be able to review each match while submitting the corresponding match's scorecard.

Scroll down to the 'Reviews' section in the Editable scorecard view for a match.

Note: The 'View All Reviews' button is only visible to the league admin. 

The actual button displayed will depend on the user's role. For example, the umpires will only see the 'Umpires Review' button.

As such, reviews are visible only to the user submitting them AND to the league admins. The reviews are NOT anonymous, the user id is captured along with the review content.

Clicking on the 'Home Team'  review form shows:

While the Umpire's review form looks like this:

Once the reviews are submitted, the scorecard shows the list of reviews:

This allows everyone with access to the editable scorecard the list of reviews. 

Again, note that the contents of each review are ONLY visible to the user who submitted them and to the league admins.

The submitted review content can be edited as long as the scorecard has not been approved by the league admins. After that action, the contents are locked.