Concept number one includes the D letter forms. Within the negative space that they create, there is the reference to the shaft of a roman column. Columns provide support and are symbolic of the logo being the foundation of one’s professional identity. In addition, it’s surrounded by the roman laurel wreath, which stood for victory. In common modern idiomatic usage it refers to a victory. The expression “resting on one’s laurels” refers to someone relying entirely on long-past successes for continued fame or recognition, where to “look to one’s laurels” means to be careful of losing rank to competition.
Concept number two includes the D letter forms as well. However, with a much simpler approach, but more elegant letter form. This one going for a much more sophisticated look. However, this would need some altering before it could be used. I leave it to you to figure out why.