The Broadband Tax has been on the books to have it made law for about 2 years. It has been slow progress getting it to be formally passed into law.
I guess you already know what the other parts are but in case others don't:
USO is to be made into the USG
Simply put the Universal Service Obligations (USO) was the previous obligation to provide an equitable connection service and previously Telstra were the USO carrier.
From the ACMA site "The universal service obligation (USO) is the obligation placed on universal service providers to ensure that standard telephone services, payphones and prescribed carriage services are reasonably accessible to all people in Australia on an equitable basis, wherever they reside or carry on business. This includes services for people with a disability, as covered under the Disability Discrimination Act 1992.
As the primary universal service provider (PUSP) Telstra is responsible for the USO in Australia. Information on Telstra's USO website indicates how Telstra intends to fulfill its PUSP obligations, including fulfilling its obligations to people with a disability, people with special needs and eligible priority customers.
The losses from supplying loss-making services in the course of fulfilling the USO are to be shared among carriers."
Under the NBN the standard telephone service is no longer standard and instead we have an internet connection with the phone service an add on to that. The USG (Universal Service Guarantee) is developed to recognise this shift in technology. These USG services will also have to support voice calls on fixed line and fixed wireless networks, but not satellite.
Instead of Telstra having the main/only responsibility for USO, under USG it now will be NBN Co and it will be designated as the primary "Statutory Infrastructure Provider" (SIP). Other carriers will be able to be SIPs where appropriate (for example in new developments).
From the Govt comes this "The new SIP obligations will ensure that every Australian can access high-speed broadband as the NBN is rolled out." and what do they define as high speed "SIPs will have to offer a standard wholesale broadband service supporting peak speeds of at least 25 Mbps download and 5 Mbps upload." I really don't define that as high speed but each to their own definition.
The Govt released an article about all the reforms in June 2017 and the following is an excerpt from that "The Regional Broadband Scheme (RBS) will provide sustainable funding for the loss-making National Broadband Network (NBN) fixed wireless and satellite networks in regional Australia." This is partly what the Broadband Tax will help fund, it is also used to pay back some of the implementation costs of the NBN.
Currently the Tax will be $7 per month but in the first year can be raised to $10 per month by the Minister, after this first year it will be indexed to the CPI. So in the long term we, the users, will pay for the NBN cost of our own connections (but never own them) and then it will be sold to private enterprise and the Govt will recover that money to general revenue.
If you move into a new development you will also be charged a further one-off $300 to connect to the NBN or comparable SIP to help offset the infrastructure costs.
Further into the article "The RBS is not a new cost for NBN users – it is already built into existing NBN broadband prices today. The RBS simply makes NBN Co's internal cross-subsidy transparent instead of opaque, and creates a level playing field by spreading this cost across all NBN-comparable networks.
It is estimated that 95% of the RBS will continue to be paid for by NBN Co, whereas today it is 100%. The remaining 5% will be paid for by competing NBN-comparable wholesale broadband networks."
I hope that helps others to understand all the acronyms.