SPSI 

SPSI is a common term used in the toilet paper industry that stands for Shit Per Square Inch. This is in reference to how much excrement a single piece of toilet paper can absorb/contain without it making contact with either the user's hand or any other outside source. SPSI is commonly used to better understand the quality of the toilet paper as a higher SPSI results in a better quality TP. SPSI is still a relatively new concept in toilet paper industry but consumers can expect toilet paper companies to begin displaying the SPSI level on their product's in as early as 2017.
SPSI is measured in shit units(SU) as well as Excrement Units(EU) and more uncommon Poop Units(PU).
We are currently in contact with multiple toilet paper products such as Charmin and Cottonelle to determine their SPSI and from our extensive research we have determined that an average level of SPSI is around 6 SU. We anticipate the giants of the toilet paper industry to be much higher than this number

SPSI was created from extensive research by three astute college students to better determine the quality of toilet paper. These shrewd students are dedicated and hardworking to make the toilet paper industry more accesible to anyone. They are credited as follows @Jsilky_ @Jrector20 @mvorndran2501
SPSI is still in the research phase of development. You patience on the development of this concept is appreciated

Dude, the SPSI of that Charmin in your bathroom is through the roof!

SPSI by JSilks October 12, 2016

SPSIMP 

Acronym for:
Someone put shit in my pants.

After I sharted I screamed out "OMG FFS SPSIMP".

SPSIMP by Frank October 29, 2004