Here are links to some relevant IRS documents:

Form W-9: Taxpayer ID and Certification
1994 determination letter (1076) from the IRS, granting tax exemption
2003 advance ruling letter (2275) from the IRS, granting public charity status
2008 determination letter from the IRS, granting public charity (section 509(a)(1)) status as of 1/1/2003

Form 990 for 2023
Form 990 for 2022
Form 990 for 2021
Form 990-EZ for 2020
Form 990-EZ for 2019
Form 990-EZ for 2018
Form 990-EZ for 2017
Form 990-EZ for 2016
Form 990-EZ for 2015
Form 990-EZ for 2014
Form 990-EZ for 2013
Form 990-EZ for 2012
Form 990-EZ for 2011
Form 990-EZ for 2010
Form 990-EZ for 2009
Form 990-EZ for 2008
Form 990-PF for 2007
Form 990-PF for 2006
Form 990-PF for 2005
Form 990-PF for 2004


Relevant part of Incorporation Certificate