There were several printings and versions of the first eighteen issues that have led to much confusion and disagreement in the industry.
Overstreet has historically noted that "1-9: Reprints; has "reprint" in upper left hand corner of cover or on inside or price and number inside a diamond with no date or UPC on cover; $.30 and $.35 issues published." However, this has recently been contested by many sources as erroneous.
The rising belief is that the Diamond price printings (as opposed to the box/square price Newsstand printings) are all Western Publishing Company (aka Whitman editions) and that the first Diamond price printings are also first printings (30c for #2-4 and 35c for #5-18, it is unclear if a genuine first print Diamond #1 exists).
CCL typically lists Whitman printings as variants and has chosen to do so in this title as well, noting "Whitman Cover" in the captions for the first eighteen issues. All subsequent diamond price box covers are simply Direct Market covers. As CCL does not list variants between Direct Market and Newsstand covers (without a significant secondary market price difference), only one cover will be entered for each issue.
Additionally, with the confusion and contradictions in the market, CCL has chosen to list both the first Newsstand and first Diamond price printings as first prints and all others as second printings.