Most Tibetologists use a transliteration often attributed to Turrell V. Wylie ("A standard system of Tibetan transcription" in: Harvard journal of Asiatic studies 22 (1959) pp. 261-267). Tibetan terms can also be searched and retrieved in the catalogue in accordance with the Romanisation Tables of the Library of Congress. The advantage of this scheme is that letter combinations instead of diacritics are used for distinction. A weak point, however, lies in the fact that the twenty-third (འ) and the thirtieth letter of the alphabet (ཨ) are not expressed by what they are in the logic of the script, i.e. consonants. Therefore, the system has been slightly modified to render the Romanisation table for the thirty Tibetan letters as follows:
In order to achieve an adequate indexing of Tibetan keywords in the catalogue, two or more syllables which constitute lexically relevant terms are hyphenated. The process of segmenting syllables into meaningful words is briefly described here.
Tibetan syllables can be classified into stems or elementary syllables and enclitics. Stems can be found at the beginning of a sentence while enclitics cannot be used initially. They are commonly called particles and will always follow another syllable. A rough distinction is one between nominal and other particles. Nominal particles are used for the formation of nouns while the other particles are relevant for expressing syntactical relations of various kinds. With this, we arrive at three categories of syllables indicated by the letters A, B, and C:
For particles other than nominal particles, a separate spelling is used. When looking for particular terms or concepts in an alphabetical index one would normally not entertain entries increased by inflectional distinctions such as cases or other purely syntactical information. There are only two cases where it is natural to connect one of the other particles, namely case particles, with a preceding syllable as an exception to the rule. One is a number of adverbs, the other is if case particles are used within personal names:
Word spelling of the rab-tu type is restricted to two-syllable adverbs. Hence we write rab-tu vbyung-ba "to enter ascetic life" but lag tu vjug-pa "to hand over" and pha-rol tu phyin-pa "supremacy". The spelling Chos-kyi implies that the term is part of a name, while "sphere of religion" is chos kyi dbyings.