Viewers are likely to be angered by fictional start-times and painfully long ad breaks during shows such as Homeland.

No, which is one of the reasons that ad breaks appear to be longer, and indeed, often are longer. "Non-program matter" includes paid advertising, but excludes program and channel promos and in-program pop-up promos.

Q What about programs on secondary channels, such as GO! and 7Mate?

Fifteen minutes per hour between 6pm and midnight, 16 minutes at other times.

Q. What are the commercial broadcasters proposing?

The CEOs of Seven and Nine have proposed lobbying the federal government to have the limits lifted to 20 minutes per hour in prime time. However, a spokesman for Ten, the third-ranked commercial network, says it will oppose the push amid concerns of a viewer backlash and fears that Seven and Nine are exploiting their leads in the ratings.

Q. How do Australian rules compare with those of other countries?

Typically a one-hour show in the US will contain 42 minutes of program content, while a half-hour show has 22 minutes; the rest of the slot consists of ads and promotions. In many European countries, ad breaks are longer but less frequent and are limited to a total of 12 minutes per hour. In the UK, the average is seven minutes per hour with a cap of 12 minutes in prime time.

Q. For imported programs like Homeland or Downton Abbey, how would these extra ads be squeezed in?

All shows are edited with "built-in" ad breaks. As programs on prime-time commercial TV rarely if ever run to the time listed on schedules, lengthening an ad break by an extra few minutes is unlikely to cause any further scheduling problem. However, it's guaranteed to anger viewers who are already frustrated by fictional start-times and painfully long ad breaks, and it's likely to increase the growing rate of "time-shift" viewing, whereby viewers record their favourite shows and watch them later, fast-forwarding through the ad breaks. There are anecdotal claims that imported shows are trimmed or "sped up" in order to lengthen the ad breaks. In some instances, this is the result of international versions of a show being several minutes shorter than the one that airs domestically - this is particularly true of British television programs.

Q. Who regulates and oversees the ad regime?

According to the current code of practice, complaints about matters related to advertisements must be made to the station first. Complaints may be referred to the Australian Communications and Media Authority if the complainant is dissatisfied with the station's response or if no response is received within 60 days.

Q. How is the government likely to view the proposed ad increase?

The Communications Minister, Malcolm Turnbull, has made it clear on other regulatory changes that if the industry cannot agree on a unified approach, the government will not consider any changes. Media analyst Steve Allen says Ten "will never agree to this, on understandable grounds".

Q. What about the public broadcasters - what are ABC and SBS's ad regimes?

SBS controversially introduced in-program ad-breaks in 2007 (prior to that, ads screened only between programs) as a way of increasing revenue that could be channelled into program-making. The SBS code stipulates that advertisement and sponsorship announcements must not run for more than five minutes in total per hour. The ABC does not air commercials. Though there are voices within government advocating for the ABC to become commercialised, the commercial networks are certain to oppose any such move as it would potentially deprive them of ad share.

Q. Might the rules about ads have other effects on commercial TV?

It's worth remembering that this is an opening gambit, and that the industry might agree on lobbying for something more "palatable", say, an extra minute or two per hour, which would still significantly boost a network's bottom line. On the whole, however, commercial TV remains the biggest game in town, with pay-TV penetration steady at around 30 per cent of households and hybrid online services struggling to gain a foothold in the Australian broadcasting market. And with first-run, home-grown reality shows and news shows driving their ratings, the networks have never been in a stronger position.