Some Maozhang were issued in themed series or sets, and these became especially popular as presentation gifts during 1968-69. In some sets the badges were numbered (e.g. 1-10, 2-10, etc), as the Mao's Career set. Others were issued in specially made containers that would only hold a specific number of badges, such as the Garments Import and Export set. In the absence of numbering or the original container it can be difficult, if not impossible, to determine the extent of a series or set.