The latest version of the International Table Tennis Federation (ITTF) handbook which includes current match rules, can be accessed through the ITTF website at www.ittf.com/handbook.
We would like to draw attention to a few rules in particular that players should familiarise themselves with as summarised below. A detailed description can be found within the ITTF handbook as refenced.

Advice to Players – this rule was changed in 2017 to allow players to receive advice at any time during their match except during rallies and provided play is not thereby delayed.
3.5.1.3 Players may receive advice at any time except during rallies provided play is not thereby delayed (3.4.4.1); if any authorised person gives advice illegally the umpire shall hold up a yellow card to warn him or her that any further such offence will result in his or her dismissal from the playing area.
Please refer to section 3.5.1 of the handbook for full details.

The Expedite System – did you know there is a time limit of 10 minutes per game. If a game is unfinished after 10 minutes and fewer than 18 points have been scored (i.e. score has not reached 9-9 or 10-8), the game will continue to a conclusion using the expedite rule.
2.15.4 Thereafter, each player shall serve for 1 point in turn until the end of the game, and if the receiving player or pair makes 13 correct returns in a rally the receiver shall score a point.
Once introduced, the expedite rule shall remain in operation until the end of the match.
Please refer to section 2.15 of the handbook for full details regarding rule implementation during match.

The Service – are your serves legal or do they fail to meet the current requirements. Section 2.6 of the ITTF Handbook describes in detail what is required to make a legal service. All players should ensure they are familiar with these requirements either when playing or umpiring.
The following link provides a demonstration of the correct service requirements.
Demonstration of Service Rules by PingSkills

New Rubber Colours Allowed – ITTF have approved the use of four new colours for table tennis rubbers commencing October 2021. In addition to black and red, the new approved colours consist of pink, violet, green and blue. They may be used instead of red; one side of the racket must still be black. All rubbers to be approved by the ITTF before use. See the “Equipment” page on the ITTF website for a complete list of approved equipment including rubbers.