Number Line
Number Line
[Number line ranging from −1 to 10.] [Arrow pointing left, towards negative numbers] Negative "imitator" numbers (do not use) [Line right before the number one] 0.99... (actually 0.0000000372 less than 1) [Line at the golden ratio.] Φ  Parthenon; sunflowers; golden ratio; wait, come back, I have facts! [Line at a region between two and 2.2] forbidden region [Line at Euler's number.] e [Line a bit before 3] 2.9299372 (e and pi, observed) [Line at π.] π [Line at 3.5 with ᛟ as the numeral] Gird – accepted as canon by orthodox mathematicians [Line a bit after 4.] site of battle of 4.108 [Blob between 4.5 and 6.5 labeled unexplored.] [Line at seven.] Number indicating a factoid is made up ("every 7 years...", "science says there are 7...", etc) [Line at eight.] Largest even prime [Line at 8.75.] If you encounter a number higher than this, you're not doing real math

Once again, Randall seems to be just messing around, this time with a number line.
The title text is a literalism joke; at the time the comic was published, all Wikipedia articles with incomplete lists began with the message template "This list is incomplete; you can help by expanding it." In the case of the List of numbers page, one could infer the absurd notion that Wikipedia wanted to have the list include every number from negative infinity to infinity. But because all Wikipedia articles are necessarily finite, such a list would always be incomplete, no matter how much it was expanded. It may also be referencing his previous statements about Wikipedia being the home of compulsive list-makers, who make the most astonishingly complete lists imaginable.
As of 2021, Wikipedia's List of numbers page, as well as all pages including lists that cannot ever reach a state of completion, are headed by the message template "This is a dynamic list and may never be able to satisfy particular standards for completeness. You can help by adding missing items with reliable sources."
[Number line ranging from −1 to 10.] [Arrow pointing left, towards negative numbers] Negative "imitator" numbers (do not use) [Line right before the number one] 0.99... (actually 0.0000000372 less than 1) [Line at the golden ratio.] Φ  Parthenon; sunflowers; golden ratio; wait, come back, I have facts! [Line at a region between two and 2.2] forbidden region [Line at Euler's number.] e [Line a bit before 3] 2.9299372 (e and pi, observed) [Line at π.] π [Line at 3.5 with ᛟ as the numeral] Gird – accepted as canon by orthodox mathematicians [Line a bit after 4.] site of battle of 4.108 [Blob between 4.5 and 6.5 labeled unexplored.] [Line at seven.] Number indicating a factoid is made up ("every 7 years...", "science says there are 7...", etc) [Line at eight.] Largest even prime [Line at 8.75.] If you encounter a number higher than this, you're not doing real math
