Both in and anti are in(verted). type rubbers.
So anti is also in(verted)
The name anti is the least confusing of all 4 rubber typr names
It would make sense to call rubbers named as "in" as spinverted (Spin in) as in spinny inverted and call "anti" as "anti in"
The other 2 names for rubber types, "out" & "long" are more confusing (by design by ITTF)
Because to start with
both "out" and "long" are pips "out" rubbers.
So it would have made little sense at least to call them "short" and "long"
Unfortunately all "long" pips were banned in 1977 when ITTF set the maximum allowed pip length to 2.0 mm.
But ITTF does not want the choppers, the most ignorant fools of table tennis, to know this.
That is why ITTF had been calling the previously long pips as long pips for more than 43 years now to deceive the chopper.
Because, keep in mind that the maximum allowed pip length for ANY pips is 2.0 mm. It is not like the "long" pips type are longer than the so called "short" pips,
The only difference is the width of the pips. But iTTF doe snot want the pips players especially the choppers to understand this.
This is why ITTF has cleverly & brilliantly used the phrase "Aspect Ratio" to confuse the pips players, as if the phrase "Aspect Ratio" is some sort parameter derived from relativistic quantum mechanics or something LOL
So the real difference between long and out is that long is not really long but they are actually slimmer & out is really not short but they are actually wider.
So it would make more sense to call the ITTF LARC pips as wide pips & slim pips A.
Also since the wide pips are usually stiffer and slim pips are more flexible , you can also call them stiff pips and flex pips
But for heavens sake, stop referring to useless social pips on ITTF LARC as "long" pips. They are not by a long shot (pun intended)
"Long" pips were banned in 1977 , almost immediately as soon as they arrived around mid 1970's (mostly mostly due to the legendary chopper Liang Geliang & few other emerging choppers ), to shut down their pips capabilities almost immedietely. The brutality & oppressionof pips players by
robotNazis has started about 40 years ago and yet pips players , especially the now almost extinct choppers, have no freaking clue