University College London
All pronunciation dictionaries make use of abbreviatory conventions to save space. The use of devices such as italicization, superscription, and parenthesization makes it possible to cater for several different phonetic forms without retranscribing the whole of the variant pronunciation.
EPD, LPD and ODP exploit these possibilities in various ways, as do some general dictionaries. This allows them to varying extents to represent lexical pronunciations other than the mainstream variant or the variant judged most suitable for EFL purposes.
To a minor extent this is relevant to the coverage of regional or social variants, e.g. plosive epenthesis, pre-lateral effects, t-voicing. Mostly, it relates to contextual or phonostylistic variability: syllabic consonants, varisyllabicity, assimilation and elision, r-liaison, stress shift.