vinylic cations

https://doi.org/10.1351/goldbook.V06621
Carbocations having the structure $\ce{R2C=C^{+}–R}$.
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1374 [Terms] [Paper]