1. Its purpose is to maintain status quo
In Takako Sakao (f) v Ng Pek Yuen & Anor (No. 3)  2 MLJ 141, the Federal Court held:
“When viewed in its proper perspective, what s 80 is designed to address is a situation where there is either an application for leave to appeal or an appeal pending before this court the integrity of which is required to be preserved. It would be futile for an appellant or an intended appellant to prosecute his appeal or application for leave before this court if the subject matter of the appeal is dissipated or otherwise disposed of. Power is necessary in an appellate court, in particular the apex court, to preserve and maintain the status quo until the matter is finally disposed of. Section 80 does precisely that. It empowers us to make interim preservation orders to protect the integrity of an appeal or a leave application until it is finally disposed of.”
2. The Court of Appeal and Federal Court are empowered to grant it pursuant to the Courts of Judicature Act 1964
Sections 44 and 80 of the Courts of Judicature Act 1964 provide the following:
“44. (1) In any proceeding pending before the Court of Appeal any direction incidental thereto not involving the decision of the proceeding, any interim order to prevent prejudice to the claims of parties pending the hearing of the proceeding, any order for security for costs, and for the dismissal of a proceeding for default in furnishing security so ordered may at any time be made by a Judge of the Court of Appeal.
80. (1) In any proceeding pending before the Federal Court any direction incidental thereto not involving the decision of the proceeding, any interim order to prevent prejudice to the claims of parties pending the hearing of the proceeding, any order for security for costs, and for the dismissal of a proceeding for default in furnishing security so ordered may at any time be made by a Judge of the Federal Court.” (Emphasis mine)
3. The High Court can grant it if the subject matter involves property
The High Court can also grant IPOs, albeit in more narrow circumstances, namely where the subject matter involves property.
Item 6 of the Schedule to the Courts of Judicature Act 1964 seizes the High Court with the:
“Power to provide for the interim preservation of property the subject matter of any cause or matter by sale or by injunction or the appointment of a receiver or the registration of a caveat or a lis pendens or in any other manner whatsoever.” (Emphasis mine)
4. It can take the form of injunctions
The Court of Appeal in Silver Concept Sdn Bhd v Brisdale Rasa Development Sdn Bhd (formerly known as Ekspedisi Ria Sdn Bhd)  4 MLJ 113 opined that:
“[Section 44 of the Courts of Judicature Act 1964] empowers this court to make interim orders to preserve the integrity of an appeal or other proceeding, including the very application under the section itself (see sub-s (2)). Such interim preservation orders may take the form of an injunction or other relief designed — in the words of the section — ‘to prevent prejudice to the claims of parties’.” (Emphasis mine)
In Fawziah Holdings Sdn Bhd v Metramac Corp Sdn Bhd(previously known as Syarikat Teratai KG Sdn Bhd)  1 MLJ 435, the Court of Appeal ordered an injunction “… in the form of a post judgment Mareva injunction.”
Meanwhile, in Subashini a/p Rajasingam v Saravanan a/l Thangathoray and other appeals  2 MLJ 147, it was in the form of an Erinford injunction.
5. It would not be defective if granted by two (or more) judges of the Court of Appeal/Federal Court
In Wan Khairani bte Wan Mahmood v Ismail bin Mohamad & Anor  4 MLJ 409 (“Wan Khairani”), the 1st Respondent argued that the interim preservation order granted by the Court of Appeal was defective as it was granted by two Court of Appeal judges.
Tengku Baharudin JCA (later FCJ), in delivering the majority judgment in Wan Khairani, held:
“Kemusykilan RP tentang perintah dibuat oleh dua orang hakim dijawab oleh s 38(1) CJA itu sendiri yang dimulakan dengan perkataan-perkataan ‘Subject as hereinafter provided’. Seksyen 44 CJA adalah salah satu peruntukan terkemudian yang dimaksudkan di mana keputusan yang dibuat oleh seorang hakim dianggap sebagai keputusan Mahkamah Rayuan — lihat sub-s (2). Jika perintah sedemikian sah dibuat oleh seorang hakim, maka mana-mana hakim dalam panel Mahkamah Rayuan boleh membuatnya. Ekorannya perintah sedemikian yang dibuat oleh dua orang hakim Mahkamah Rayuan adalah teratur dan sah.” (Emphasis mine)
6. It cannot be granted if, in effect, it would render the appeal nugatory/academic
In Taipan Focus Sdn Bhd v Tunku Mudzaffar b Tunku Mustapha  1 MLJ 441, one of the legal questions posed to the Federal Court was:
“whether as a matter of law the Court of Appeal can make orders under s 44 of the Courts of Judicature Act 1964 which in effect renders the appeal nugatory or academic and/or is made pending the disposal of another suit which is not the subject matter of the appeal.”
The majority (2-1) answered the leave question in the negative.