With the popular use of machine translation technology in the translation industry, postediting has been widely adopted with the aim of improving target text quality. Every post-editing project needs to have specific guidelines for translators to comply with, since the guidelines may help clients and LSPs to set clear expectations, and save time and effort for translators. Different organizations make their own rules according to their needs. In this paper, we focus on comparing five sources of post-editing guidelines, and point out their overlaps and differences.