Should you capitalise "eBay" at the beginning of a sentence? [duplicate]

Brand names

You should never change a brand name. 'iPhone' should always be spelled as 'iPhone,' no matter where in the sentence it is. 'IPhone,' 'iphone,' 'I-phone,' 'i-phone' or 'I phone' are always wrong. 'iPhone' is the only good one:

Good

iPhones are the best selling smartphones.

Wrong

IPhones are the best selling smartphones.

Terrible

Iphones are the best selling smartphones.

This is the same for all brand names, but this can also be for other (nick)names invented by people, for example 'rms' which should always be spelled lowercase.

Exception

There could be, however, one exception, when the sentence is spelled in all caps, usually for styling purposes:

Good

IPHONES ARE THE BEST SELLING SMARTPHONES.

Acceptable

iPhones ARE THE BEST SELLING SMARTPHONES.

Wikipedia suggest that eBay is the correct usage.

eBay announced that starting in March 2008, eBay had added to...

However, I would be interested to see if the same convention applies with abbreviations like mRNA

Again, Wikipedia suggests the same.

mRNA is transcribed from a DNA template, and carries coding information...

However, that's not to say that these are the "official" rules in any capacity.

iPhone is tricky. You have to capitalize it the way Apple does. It is a product therefore has to be labeled the way the brand does. Technically anyway you write it would be correct but if you want to be exact then capitalize the "P" only even it is a the head of a sentence.