ISO 519:1992 Preview
Photography -- Hand-held cameras -- Flash-connector dimensions
This standard was last reviewed and confirmed* in 2013.
*Therefore this version remains current
To accommodate some freedom in design and use of materials, the dimensions of the cone-shaped tip of the plug pin and the protruding length of socket insulation and outside contact are not specified. Both influence the overall length of electrical coupling, however, and they should not be excessively long.