The attitudes of employers is a relevant consideration in the exercise of the Commission's discretion under s 72A of the Act when determining applications concerning coverage of employee organisations.

In construing the eligibility provisions of a registered organization of employees, regard may be had to common understanding among people concerned with relevant industries of the ordinary application of words used, evidenced by previous use in the organization's rules, statutory provisions, decisions, and industry papers. The ultimate conclusion as to the legal effect of the words is a question of law.

The phrase 'metalliferous mining' in the context of the A.W.U.'s eligibility provisions encompasses not only the actual process of mining and treating minerals but also the preliminary construction of mine, treatment plant, and associated facilities before extraction of minerals commences.

Section 41A(2) was enacted to prevent demarcation disputes and restrict unions from extending coverage to employees they are not constitutionally entitled to represent, not to prohibit multi-union agreements.

The test in s.158(4) involves 'broad value judgements of no particular precision' and requires both that another organisation be one to which relevant employees could 'more conveniently belong' AND that such organisation would 'more effectively represent' them—both conditions must be satisfied.

'More conveniently belong' is oriented towards the perceived convenience of the employees themselves, while 'more effectively represent' concerns the relative capability of organisations to effectively represent the industrial interests of that class of employees.

Evidence relating to purging of a union's membership register in the context of demarcation proceedings may be admitted where the union files particularised information about affected members, including name, occupation, employer and date of purging.

The Full Bench must refuse a rule alteration application unless satisfied there is good reason consistent with s6 objects of the Act; overlapping eligibility should be discouraged to avoid demarcation disputes, but such alteration may be authorised if there is an undertaking from the other affected organisation and the alteration promotes objects such as s6(ag) encouraging appropriate agreements.

In determining s.158(4) objections, weight may be given to the absence of objection from relevant competing organisations.

The real issue in dispute in demarcation/representation rights cases under s 72A is whether the capacity of a union to represent the industrial interests of relevant employees is consistent with the objects of the Act in s 6(e) to discourage, so far as is practical, the overlapping of eligibility for membership of competing unions.

Where there exists another organisation to which members might more conveniently belong and which would more effectively represent them, the registration requirement is satisfied if an undertaking is accepted by the FWC to avoid demarcation disputes.

For s.19(1)(j) purposes, where objecting organisations raise demarcation dispute concerns, those concerns can be addressed by appropriate undertakings accepted by the FWC to avoid demarcation disputes arising from overlap in eligibility rules, without requiring s.19(2) formal undertaking process if no existing organisation would be more convenient or effective.