Clear British usage is

  • Direct and precise — say what you mean without filler
  • Authoritative without being pompous — confidence earned, not asserted
  • Understated — let the substance speak; do not oversell
  • Formal in structure, accessible in tone — write for the reader, not the writer
  • Specific — use exact values, named sources, documented references
  • Consistent — one voice, one spelling convention, one set of rules throughout

British usage is not

  • Enthusiastic or exclamatory — no hyperbole, no exclamation marks
  • Ironic or self-deprecating at the expense of clarity
  • Verbose — padding is weakness, not sophistication
  • Casual or colloquial in formal contexts
  • Vague — avoid weasel words, hedging and approximation where precision is available
  • Americanised — spelling, vocabulary and idiom follow British conventions throughout

Spelling Conventions

British Not Notes
Colour Color All -our endings: honour, favour, neighbour
Centre Center All -re endings: theatre, metre, litre
Organise Organize -ise endings standard in British usage
Programme Program Except in computing contexts
Licence (n.) License (n.) Licence = noun  ·  License = verb
Travelling Traveling Double-l in -elling, -illing, -ulling
Cheque Check Financial instrument only
'Single quotes' "Double quotes" Single marks preferred in British style

These represent widely accepted conventions in British English. Style guides vary — the Oxford Style Manual and New Hart's Rules are the authoritative references.