The dates shown after a name relate to the period during which the comic appeared.
There is usually a fair degree of accuracy about the starting date, but because of rights being transferred or the very gradual loss of appeal of a particular strip the termination date is often very uncertain.
The names shown refer to the originators of the character; many have continued to be created by others over time.
It is also to be noted that many of the characters appeared in both strip and book format as well as in other media.