Board of Directors or board of directors

[ahold]

I noticed that on the internet Board of Directors is often written with capitals. I even found the sentence: Anna, our Director of three years

isn't director a function here rather than a name or title and shouldn't it be written with a small d?

Any suggestions welcome.
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Thanks Katz, these links were very helpful indeed.
so it should be: Anna, our director of three years

[Katz]

(not a teacher or a native speaker)

I find this quite common in business and legal writing. It seems that we're not the only ones who are puzzled by this practice:

When Should You Capitalize Words? : Grammar Girl :: Quick and Dirty Tips ™
When Should You Capitalize Titles? : Grammar Girl :: Quick and Dirty Tips ™
Business Writing: Sales Department or sales department?
Please stop capitalizing every other word
Grammar and Writing - Capitalization of Titles

[SoothingDave]

"Director" is indeed a title.