The part of an IPO offered to the Hong Kong public. Under Practice Note 18, Mechanism A has an initial allocation of 5% of the offer shares, clawed back to 15%, 25% or 35% according to the oversubscription multiple of the public offering; Mechanism B has an initial allocation of at least 10% with no clawback, and at least 40% of the shares must go to placing tranche investors other than cornerstone investors. After any clawback the public offering is divided equally into Pool A, for applicants applying for HK$5 million or less, and Pool B, for applicants applying for more than HK$5 million. Basis: Practice Note 18; HKEX Guide for New Listing Applicants, Chapter 4.14.
The links above lead to official sources such as HKEX and the SFC. The explanation on this site summarises them and may differ from the official definition; the official documents prevail.
This page explains the HK IPO term "HK Public Offer" and links to related terms. Definitions are compiled from HKEX Practice Note 18 and the Listing Rules, for understanding subscription rules only — not investment advice.