A classy distinction. Our big takeaway is that trademark law only protects marks in regard to the class of goods or services being offered under that mark. That's why you can wear American Apparel while you're flying American Airlines, or look for jobs at Monster.com while listening to speakers connected by Monster cables, or fasten Arrow staples to your Arrow shirt. Only those marks that are rock stars in the trademark world -- think Nike or Coca-Cola -- can claim a likelihood of expanding into a broad array of goods and services, and more importantly can prevent another company's use of their famous mark because a third-party use dilutes it.
Domain names and trademarks. A registered trademark owner can only dislodge a domain name holder if the domain name is identical or substantially similar, and the domain name owner acquired or is using the domain name in bad faith. That generally means the domain name holder is exploiting the trademark owner's rights. You won't have that problem because you have a bona fide intent to use the mark for fashion accessories not to compete or trade off the software company's name.