It's not 300 words, it's 300 characters, which includes spaces and punctuation. You are a senior member, i.e. been a member for 15 days and a post count of 75. Check out the membership hierarchy which explains the permissions for each level of forum membership. You might consider becoming a site supporter which for as little as $5 a month, increases those permissions quite a bit as well as gives you access to other sections which are restricted to supporting members only.