We will provide a theory/platform-neutral framework for representing idiomatic expressions. Previous analyses on idioms, including those for some systems implemented on the basis of specific theories and platforms, are not flexible enough to deal with the gradational nature of syntactic and semantic anomalies of idioms, and/or are not explicit enough to be useful in natural language processing. We will overcome these problems by introducing some theory-neutral notational mechanisms, which apply to regular phrases, to capture the peculiarities of idioms. The present framework will become a very useful guide in building effective computational resources for a variety of languages, although we are focusing on the analysis of English and Korean idioms. One of the strong points of our approach is that we can formalize precisely the properties of potentially numerous different types of idioms, which is possible because we are using regular phrases built from phrase structure rules to represent the peculiarities of idiomatic expressions. The resulting resources will enhance the parsing accuracy and speed significantly, and will play an important role in disambiguation.