Cintas Corp. said it will report to shareholders on the labor practices of its suppliers, a year after its board opposed such a report...At the same time, the company has settled a defamation suit it filed earlier this year against a Boston investment firm [Walden Asset Management (part of Boston Trust & Investment)] and one of its executives [Timothy Smith], who offered the report proposal at last year's annual meeting...In a letter to Cintas dated Aug. 20, Smith said that based on the third-party audit materials provided by Cintas, "I would not have described this facility as a 'sweatshop,' and I regret any harm that may have caused to Cintas." [also refers to Domini Social Investments]