SPF

SPF can stand for:
* In science:
** Sun Protection Factor, a laboratory measure of the effectiveness of sunscreen
** Specific Pathogen Free, a term for laboratory animals known to be without pathogens
** Superplastic Forming
* In mathematics:
** Formal spectrum of a ring, a construction in algebraic geometry
* In computing:
** Sender Policy Framework, an e-mail anti-forgery system
** "Shortest Path First", another name for Dijkstra's algorithm
** Single point of failure in systems
** Sunbelt Personal Firewall, a desktop personal firewall
** "System Productivity Facility", an early version of the ISPF text editor
* In government:
** Singapore Police Force
** South Pacific Forum
** Space Power Facility, an experimental vacuum chamber for NASA
** Special Purpose Forces, highly trained and advanced soldiers
** Socialist Party of Florida, an affiliate of the Socialist Party USA
** Servicio Penitenciario Federal, the Argentine federal administration in charge of prisons.
* Mixed softwood timber coming from Spruce, Pine and Fir trees
* Summer Play Festival