Special Work Permit (SWP)
A Special Work Permit is not a Visa, but a temporary permit that allows a Visitor Visa holder the ability to do limited work in the Philippines. The holder is responsible for keeping his temporary visitor’s visa valid during his or her stay in the country.
The SWP is normally issued for 3 months and can then be renewed once for a further three months.
http://www.immigration.gov.ph/services/special-permits/special-work-permit-commercial
Other Working Visas for the Philippines:
Pre-Arranged Employees (Commercial) visa (9G)
Any foreign national wishing to work in the Philippines must obtain a valid work visa, called the 9(G) visa
a Pre-Arranged Employees (Commercial) visa under Section 9 (g) and Section 20 of the Commonwealth Act No. 613 or Philippine Immigration Act of 1940 (PIA). This is a working visa that allows employers or proprietors [in the Philippines] to employ foreign nationals with skills, qualifications and experience that may be short in supply in the Philippines.
http://www.immigration.gov.ph/faqs/visa-inquiry/pre-arranged-employee-visa
Provisional Permit to Work (PPW)
The PPW is issued to foreigners who have an application for a 9G Visa in process. The issuance of a PPW allows a Visa holder to work while waiting for the 9G visa to be issued.
http://www.immigration.gov.ph/services/special-permits/provisional-work-permit
Alien Employment Permit:
An Alien Employment Permit is a document issued by the Department of Labor and Employment which authorizes a foreign national, with a valid visa, to work in the Philippines.
http://www.ble.dole.gov.ph/faqs.asp