Dear GNU Reference https://www.gnu.org/software/gnu-c-manual/gnu-c-manual.html Section 2.2.1 and 2.2.2 on enumerations. I do not think that these are correct. To define something causes storage allocation (its creation). To declare something does not causes storage allocation (no creation). Looks like 2.2.1 and 2.2.2 are switched. Thanks Dale Noble Hi Rel Data 590 Solutions Way Suite 100. Rockledge, Florida, 32955 Office/FAX: 321-775-4001 Dale.Noble@xxxxxxxxxxxxx www.HiRelData.com