What is "for all intensive purposes"

adv. (context idiomatic US nonstandard English) Misconstruction of “for all intents and purposes”.“” in '''Common Errors in English''', by Paul Brians'''ActionGrammar''' by Joanne Feierman (found in the chapter “Mistakes Your Boss Minds the Most”, in the section “Twenty More Language Pet Peeves”, on page 26, and also listed on page 212)'''The Dictionary of Disagreeable English''' by Fiske, page 136“” Mark Israel’s '''AUE FAQ''' (September 1997)The '''Broadview Guide to Writing''' by Doug Babington & Don LePan, page 241 (3^rd Ed., 2005)'''The How of WOW: A Guide to Giving a Speech That Will Positively Blow ‛Em Away''' by Tony Carlson, page 159 (2005)'''Write Right!: A Desktop Digest of Punctuation, Grammar, and Style''' by Jan Venolia, page 112 (2001)'''Anguished English: An Anthology of Accidental Assaults Upon the English Language''' by Richard Lederer, page 178 (2006)“” in '''The Eggcorn Database''' (version 0·5), by Chris Waigl