There are lots of standardized definitions of SEO (see define query), but few that exist to define or distill the qualities that make a person a professional SEO. The way I see it, there are three ways a professional can be categorized and assigned - technical, self-constructed and peer validated.

Technical: An SEO is one who practices search engine optimization.

Self-Constructed: I practice search engine optimization as a significant portion of the professional work I undertake and am, therefore, an SEO.

Peer Validated: A community of peers in the SEO field has recognized this individual's achievement and views them as qualified for the title.

In the SEO world, these are very informal and anyone is technically allowed to call themselves what they like (and though I'll quibble later in the post with some self-titling, I don't believe any regulation should exist). However, in many other fields, primarily those with a long-established history (lawyer, doctor, law enforcement, engineer, politician), external requirements are a neccessity.

That said, the SEO community appears to be growing in its formalization. Events, organizations, and external recognition, along with the growing value and importance of the practice seem, to me, to be the driving forces at work. I love this community and always have - it's inspired me, carried me and given me so much that I can never repay enough, but I'd like to add a brief editorialization. It is my personal opinion that unless an individual has these three qualities, I would not personally peer-validate them as an SEO and would hope to be cast out should I not personally exhibit these:

1. Knowledgable in the Basics of Search Engine Operations (not just SEO, but the fundamentals of how search engines work)
2. Actively Practicing SEO by Influencing Change to Websites & Pages and Measuring the Impact
3. Consistently Formulating & Testing Theories About Metrics/Variables that Influence Search Engine Results

I've been a bit frustrated of late by the demeaning of our profession by those who do not take the practice seriously nor apply the craft with the respect it's due. And, furthermore, I'm conflicted about those who'd suggest that our field or our practice should not embrace the principles above. It seems disingenuous, even intellecutally dishonest, to claim to "optimize" for search engines, and yet be lacking in knowledge, not actively practicing (and measuring!), or refrain from critical thinking, brainstorming, forming hypotheses and testing.

Am I too harsh? Should I be more lenient? Or, do we, as a community, want to apply some standards in peer validating those who claim the title of SEO? If so... Are these the right ones?