In spite of its apparently British origins, the Barlow knife is often thought of as a quintessentially American pattern due to its popularity there beginning in the nineteenth century.
The most popular form, the lockback knife, was popularized by Buck Knives in the 1960s, so much that the eponymous term "buck knife" was used to refer to lockback knives that were not manufactured by Buck.
Some credit card knives can contain other small tools, such as tweezers, or toothpicks.
A ballpoint pen knife is generally a pen with a concealed knife inside, which can be used as a letter opener or as a self-defense weapon.
Many other combinations of large and small drop point blades, a Phillips-head screwdriver, saw, etc. Elongated knife, with a single narrow clip point blade.
Handle has bolsters at both ends, and is turned up or tapered on the opposite end of the blade.