It's an interesting pastime to check out the various "No Concealed Weapons" signage forms around Nebraska.
[Actually, they are intended for "No Concealed Handguns", but that's another whole story about the legal nature of "weapons", "deadly weapons", etc.]
Methodist Hospital [Omaha] has no signs on the two main entrance doors fed by the major overhead walkways from the parking garage. However, the other doors on the ground floor below, across from the parking garage are signed. Further. the NCW signs are on the coming out doors, not the going in doors. The coming out doors swing away in such a manner that if someone else is coming out while you are going in, you will not see the NCW sign. Their intent appears to be to post the entire premises, not just the ICUs and ERs, which do not need posting. The Methodist signage needs work to clarify their intent. Nevertheless, you could still be busted.
The Westwood Shopping Center at 120th and Center [Omaha] has NCW signs posted at the main street entrances to their parking lots. Hardly the place you'd be checking for NCW signage. Yet none of the actual building doors and entrances in the entire shopping center are posted. Nevertheless, you could still be busted.
1 Valmont Plaza [Omaha] has a very high quality white frosted etched glass NCW sign posted well to the right side of their main entrance door. Hardly where you'd look. Hardly looks like NCW posting. Looks like some sort of a financial institution logo, until closely examined. Yet, you could be busted.
And many, many more such instances are seen around town.
At a glance, any NCW sign could be mistaken for the "No Smoking", "No Trucks", "No Parking" and similar "No Whatever" signs commonly encountered. You've got to be alert and careful, considering the potential penalties, which also include legal fees and loss of CHP.
Nebraska CHPs carrying on posted premises face an immediate NCW violation charge which carries a 3rd Class Misdemeanor penalty. By contrast, if Iowa CCWs violate Iowa signage, at first they only may be asked to leave the premises. If they do so immediately, then there's no bust and no penalty. The incident only becomes a violation if you stay after being asked to leave. Even then, it's only a trespassing charge.
Conclusion: Nebraska NCW signage and rules are tricky and put legit CHPs at risk; the signage rules need to be modified. [Which will no doubt generate howling and hollering from the merchant class.]