Maybe they mean the 26th consecutive month the index has stayed above 50? Either way, the manufacturing sector continuing its expanding ways is a sign the economy continues to show decent strength.
You're a genius-- that's got to be it!
IOW, it's 26 months over 50 meaning 26 months of expanding activity according to the 'secret' formula used by the ISM. There's a different formula that actually works and isn't so 'secret'. It's MSM + FR = useful information.