Former Cardiff City boss Malky Mackay and head of recruitment Iain Moody will face no action over allegations they shared racist and sexist texts.
The Football Association said it had carried out a "thorough" investigation into the language used in the messages.
It found "the communications were sent with a legitimate expectation of privacy".
But both men have been spoken to "about the inappropriateness of terms used in the messages".
The FA added in a statement: "To date, the FA's policy in cases such as this has been to not bring charges in respect of private communications sent with a legitimate expectation of privacy."
In the 11-month investigation, 27 witnesses were spoken to by the FA, which said the process was delayed by "serious concerns" over "the circumstances in which particular evidence provided to the FA had been given".
"The nature of these concerns, which the FA treats with the utmost seriousness, has necessitated significant further inquiries by the FA and the liaison with external law enforcement agencies," it said.
The board of Cardiff City will discuss the FA ruling at a scheduled meeting on Friday.
A senior club official told BBC Wales: "We will not make a statement until we have considered the matter fully."
However, chairman Mehmet Dalman said the decision was a "massive setback for football in Britain in this day and age".
Dalman told Sky Sports: "We did not ask for a life ban or anything like that, but they (Football Association) should have made it clear what they did was wrong."
Anti-discrimination group Kick It Out was critical of the decision, as was Women in Football and the Jewish Leadership Council.
Kick It Out chairman Lord Ouseley told BBC Radio 5 live: "The issue here is not now about Malky Mackay and Iain Moody, it's about the principle of where does the FA stand on these issues, along with the rest involved in football?
"There is no standard when it comes to flushing out discrimination at the top end in football."
Mackay, 43, was sacked as Bluebirds boss in December 2013 when they were just outside the Premier League relegation zone.
The following August, Cardiff alleged Mackay sent "sexist, racist and homophobic" text messages during his time as their manager. Similar claims were also made against Moody, who had been dismissed by the club for an alleged £15m transfer overspend, which he denied.
Moody left his post as Crystal Palace sporting director shortly after the allegations were made.
Mackay admitted sending offensive messages and apologised, adding he was not racist, sexist, homophobic or anti-Semitic.
The FA's ruling comes after Blackpool chairman Karl Oyston was given a six-week ban from all football activity and fined £40,000 for a text-message exchange with a fan.
Oyston, though, admitted a misconduct charge after referring to a supporter as "a retard".
The FA said it was "determined to eliminate discriminatory conduct in all its forms" and will now look to introduce a policy governing behaviour in private.
It added: "The FA is in the process of carrying out a complex review involving all stakeholders on how communications, and in particular those involving discriminatory language, which may be viewed as taking place in private should be treated in the future."
'The FA has damaged its credibility'
Kick It Out said the FA's promise to review its policy was "lamentably late in the day".
The organisation added in a statement: "The FA has damaged its own credibility and anti-discrimination policies by taking the decision not to charge Malky Mackay and Iain Moody.
"The FA needed to take a strong position to help prove football's 'zero-tolerance' approach towards discriminatory practices. Instead, we have another example of the status quo being reinforced, and discriminatory practices being allowed to flourish in 'no-go' areas such as within the exclusivity of boardrooms, training grounds and dressing rooms, and via private communication networks.
"How can anybody truly challenge discrimination and prejudiced attitudes in football with confidence now? The apparent reluctance to punish comments and behaviour considered as 'banter' or 'light-hearted culture' within these settings is entirely damaging."
Simon Johnson, chief executive of the Jewish Leadership Council, said the decision "seems at odds" with FA action over former Wigan chairman Dave Whelan's racist comments - made in defence Mackay's appointment as Wigan manager - and Liverpool striker Mario Balotelli who posted an offensive picture on Instagram.
A Women in Football (Wif) statement also called for the FA to "bring it policies into line with other sectors". It said: "Wif believe that privately discriminating against those with protected characteristics is no less dangerous than publicly doing so."