The Welsh Rugby Union says it is "surprised" England prop Joe Marler escaped punishment for his "Gypsy boy" comment to Wales prop Samson Lee.
Marler, who also avoided any action after being charged with striking Rob Evans, apologised after making the comment in England's win over Wales.
Lee, from the Traveller community, said he accepted the comment as "banter".
"We are surprised by the decision of the Six Nations disciplinary hearing," a WRU statement read.
"We stand by our belief that that there is no place for the use of racist language in sport.
"Clearly this incident has raised broader issues for the game of rugby which require follow up and which we are undertaking directly with Six Nations."
Marler has been named on the bench for England's final match of the Six Nations against France in Paris on Saturday.
Six Nations Rugby said in a statement it was "aware of the seriousness of Mr Marler's comment and does not in anyway condone what was said" but accepted it was said "in the heat of the moment".
|Six Nations schedule|
|Date (All times GMT)||Fixture||Coverage|
|Sat, 19 Mar (14:30 KO)||Wales v Italy||BBC One, S4C and BBC Radio|
|Sat, 19 Mar (17:00 KO)||Ireland v Scotland||ITV and BBC Radio|
|Sat, 19 Mar, (20:00 KO)||France v England||BBC One and BBC Radio|
It added that Marler "deeply regretted what he had said", had "immediately and unprompted apologised to Mr Lee" and noted that England head coach Eddie Jones "had reprimanded Mr Marler and reminded him of his responsibilities as an international rugby player".
Campaigners from the Traveller community - and figures inside the sport - had been critical of Marler for making the comment and called for a ban.
There was also criticism aimed at Jones and Wales head coach Warren Gatland for their responses to the incident.
Gatland subsequently apologised for describing it as "banter".
Wales' defence coach Shaun Edwards said: "Well I can't speak for myself, but I speak for the organisation (WRU).
"We don't condone any sort of discrimination whether it be race, religion or sexuality etc.
"As an organisation we probably slightly disagree with it but a decision has been made. Move on."
Asked about the incident where Marler appeared to strike Wales prop Evans with his elbow, Edwards replied: "I didn't think it was that bad."