To be valid, an administrative issuance, such as an executive order, must comply with the following requisites:

(1) Its promulgation must be recognized by the legislature;

(2) It must be promulgated in accordance with the prescribed procedure;

(3) It must be within the scope of the authority given by the legislature; and

(4) It must be reasonable.

—Hon. Executive Secretary, et al. vs. Southwing Heavy Industries, Inc., et al., et seq. (G.R. Nos. 164171 and 164172, 20 February 2006)