Wozzat hole?

[Mike Arman <armanmik@n-jcenter.com>]

Noticed a small hole with rubber grommet directly under the gas gauge on my
86 non-turbo 5 Ks. Looked in Haynes - no photo, no info (no surprise,
either). Looked in owner's manual, no illustration, no information - pix of
instrument panel does not match the car (no real surprise there either).

Could someone check the Bentley and tell me what this is? Adjustment for
fuel gauge? Alignment adjustment for laser-guided anti-SUV rockets? A
snare, trap and delusion for the unwary?
  
(Yes, still wondering about the translation on Brett D's Latin sig line. . . )

Best Regards,

Mike Arman