Marquee allowances, the abolishment of the second tier salary cap and transfer windows are all ideas being considered as the NRL completes a sweeping review of its salary cap.

NRL figureheads have met with major stakeholders including commercial sponsors, players, clubs and media at Rugby League Central in the past few days in a bid to improve the oft-maligned cap.

Chief Operating Officer Jim Doyle said the review had been overwhelming success.

"There's no one particular thing that is being looked at. There are multiple things that we're looking at implementing but one of the key things over the past few days is that engaging with the stakeholders has been great," Doyle said.

"It was very important – rather than sit in a dark room with two or three people, make a decision and implement it – to engage as many stakeholders as we could.

"We had a couple of sessions yesterday, firstly with player managers and then in the afternoon with the media. The day before we met with commercial partners of our clubs and sponsors and we're getting a lot of input from them."

One of the biggest points discussed was the implementation of a transfer window – not unlike those used in England's Premier League – giving clubs and players a specific period during the year to offload and sign players.

The aggrieved second tier cap, which this year limited first grade opportunities for rising stars Matt Moylan from the Panthers and Luke Brooks from Wests Tigers, was also one of the major talking points.

The marquee player allowance, which currently stands at $550,000, could also be increased.

Doyle said the NRL was, and needed to be, open to all ideas.

"Whether it's marquee players allowance, whether it's second tier cap or whether it's injuries or player loyalties, everything was discussed in the presentation and we're definitely open to all of them.

Most of the aforementioned alterations aren't expected to be in place until the 2015 season, but Doyle said the NRL wants the overhaul to be completed by the end of this year.

"Some of that stuff could be implemented next year, but the majority of it is for the years ahead. Either way, we want to get it finished by the end of the year," Doyle said.