Your trade mark must be unique. It can include:
words
sounds
logos
colours
a combination of any of these
Your trade mark can’t:
be offensive, eg contain swear words or pornographic images
describe the goods or services it will relate to, eg the word ‘cotton’ can’t be a trade mark for a cotton textile company
be misleading, eg use the word ‘organic’ for goods that aren’t organic
be a 3-dimensional shape associated with your trade mark, eg use the shape of an egg for eggs
be too common and non-distinctive, eg be a simple statement like ‘we lead the way’
look too similar to state symbols like flags or hallmarks, based on World Intellectual Property Organization guidelines