Cacuminal

1942, George Leonard Trager, Studies in Linguistics, Volumes 1-7, page 52, /L/ and /N/, slightly more cacuminal than the alveolar series, are very rare, and occur only in word-final position.

The cacuminal s is produced by raising the tongue-tip to a point behind the alveoli, with a concavity in its upper surface;

1992, Anatoly Liberman, Vowel lengthening before resonant + another consonant and svarabhakti in Germanic, Irmengard Rauch, Gerald F. Carr, Robert L. Kyes (editors), On Germanic Linguistics: Issues and Methods, Trends in Linguistics: Studies and Monographs 68, page 190, It is a trill, because the choice can be only between a cacuminal trill or a cacuminal lateral, but cacuminal l already exists in the system […] .