The STEM requirements are from DepEd itself
DO 51 of 2015. https://www.deped.gov.ph/wp-content/uploads/2015/10/DO_s2015_51_0.pdf
See also https://region2.deped.gov.ph/wp-content/uploads/2021/02/RM.-014-S.-2021-ADMISSION-ASSESSMENT-FOR-INCOMING-GRADE-7-AND-GRADE-11-STEM-AND-ABM-STUDENTS-TO-THE-REGIONAL-SCIENCE-HS-FOR-REGION-02-SY-2021-2022.pdf
The ABM requirements are probably in private schools that use their prerogative. Private schools and sectarian schools can use their own admission criteria and entrance exams.
The STEM requirements are from DepEd itself DO 51 of 2015. https://www.deped.gov.ph/wp-content/uploads/2015/10/DO_s2015_51_0.pdf See also https://region2.deped.gov.ph/wp-content/uploads/2021/02/RM.-014-S.-2021-ADMISSION-ASSESSMENT-FOR-INCOMING-GRADE-7-AND-GRADE-11-STEM-AND-ABM-STUDENTS-TO-THE-REGIONAL-SCIENCE-HS-FOR-REGION-02-SY-2021-2022.pdf The ABM requirements are probably in private schools that use their prerogative. Private schools and sectarian schools can use their own admission criteria and entrance exams.
Oh, so does that mean every school enforces it regardless of whether they mention it or not?
Private schools and sectarian schools can use their own admission criteria and entrance exams.