Australia's CASA has a Civil Aviation Advisory Publicaton (CAAP) dealing with Aircraft Landing Areas (ALA)
In Oz anyone can designate an area for the use of a/c (subject to the usual council bureaucrats, if applicable). An ALA is such a strip ie not licenced or subject to any particular oversight by any regulatory authority.
The relevent CAAP gives guidance & recommendations concerning suitable criteria.
Don't have the specific CAAP number but CASA probably has it on their website
www.casa.gov.au