* Important
There are a few scattered posts of bare-head jack knives ....... with no Barlow to be seen.

I love jack knives and a Barlow is a jack knife ..... but ..... many jack knives are not a Barlow.
Take a look at yours and see if the bolster is roughly one third the length of the knife or on a grandaddy, about one fourth the length of the knife.
I won't call out any individual posts due to my laxed rules and not wanting to embarrass anyone.
Barlow defined by Case :
This traditional jack knife pattern dates back to 18th century England, and the popularity it enjoyed overseas as a hard-working and affordable tool option eventually brought it to the United States during the mid-to-late 19th century. Its design meant that individuals from all walks of life could enjoy the diversity and utility of the Barlow, no matter the trade or occupation.
The Barlow ('009 pattern) was undoubtedly among the first patterns ever manufactured at Case, and the pattern has remained a historic favorite among knife fans.
The knife's extra-long bolster on the pocket end and its 'barehead' cap end gives the Barlow its distinctive look while helping to preserve the knife's overall integrity over years of use. A wide variety of handle colors and materials and varying blade configurations, including Spear, Clip, or Clip/Pen blade models.