Tokyo - World Rugby issued a rare criticism of refereeing standards at the World Cup on Tuesday after a number of controversies in the tournament's opening days.
The governing body said there had been "initial challenges" with technology and communications between match officials at the tournament in Japan.
Several incidents have been missed by officials - and shared widely on social media - since the tournament kicked off on Friday.
"Following the usual review of matches, the match officials team recognise that performances over the opening weekend of Rugby World Cup 2019 were not consistently of the standards set by World Rugby and themselves," a statement said.
"But World Rugby is confident of the highest standards of officiating moving forward."
Reece Hodge's apparent high shot on Fiji's Peceli Yato went unpunished at the time, but the Australia wing was later cited and will face a disciplinary hearing on Wednesday.
Footage of All Blacks captain Kieran Read's head-high, off-the-ball tackle on South Africa's Pieter-Steph du Toit, unnoticed by officials, has also drawn much comment online.
And Louis Picamoles appeared clearly offside when he made a crucial interception in France's narrow 23-21 win over Argentina, whose coach later slammed the officiating.
Just an hour after the World Rugby statement, refereeing was again under the spotlight as Samoa and Russia played out a bruising encounter in Kumagaya that saw three yellow cards.
For the first two yellows, both for high tackles, French referee Romain Poite very deliberately followed World Rugby's new protocol for policing high tackles with the help of his Television Match Official (TMO).
In both instances, Poite decided there was a "mitigating" reason against giving a red card, as the player being tackled - fullback Vasily Artemyev on both occasions - had stooped as the hit was coming in. This saved Samoa's Motu Matu'u and Rey Lee-Lo from a straight red.
The third case, an arm around the neck from Russian prop Kirill Gotovtsev, was more clear-cut and Poite reached straight for the yellow card.
"Elite match officials are required to make decisions in complex, high-pressure situations and there have been initial challenges with the use of technology and team communication, which have impacted decision-making," World Rugby said.
"These are already being addressed by the team of 23 match officials to enhance consistency. Given this proactive approach, a strong team ethic and a superb support structure, World Rugby has every confidence in the team."