Quad Cities Housing Council 25th Anniversary Logo
This is a really clean, effective example of a common anniversary logo design style where the traditional logo is placed side by side (in this case with a small divider line) with a number mark. This number mark uses a cut out silhouette of a house to tie it back to the original logo and meaning. Along the bottom sits wording to mark the occasion.
Source:
https://www.rcreader.com/news-releases/quad-cities-housing-council-unveils-25th-anniversary-logo-launches-affordable-housing?trumbaEmbed=view%3Devent%26eventid%3D174378587