A user should disclose any relevant affiliations explicitly in an answer or in the credential that appears with the answer.
For example, if a user writes an answer about his own company or product, the answer (or answer credential) should make clear the user's affiliation with the company. This disclosure can be brief and does not need to be set off separately, as long as it is clear.
A relevant affiliation is any involvement that a reasonable observer would think is important for interpreting the views that the user expresses in an answer. Affiliations can include: financial interests and investments; memberships (e.g., being an alumnus of a school or a member of a club), or a personal history relevant to the answer (e.g., you are involved in a lawsuit with the company you are writing about). The general rule in close cases is: when in doubt as to whether an affiliation is relevant, a user should disclose it.
Otherwise, answers about something the writer is affiliated with are held to the same standards of helpfulness, explanation, and accuracy as other answers on the site.