royvsRSFConfusable pair

Which to use

“roy” and “RSF” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#3,220
“roy” frequency rank
#44,703
“RSF” frequency rank
47923
confusion score

Side-by-Side Comparison

Feature roy RSF
Definition De 1694 à 1740 : Orthographe de l’Académie française de roi. Abréviation de réacteur à sels fondus.

Where the eye mixes roy and RSF

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
roy
3 ch
RSF

Why the eye confuses roy with RSF

A purely visual mix-up. roy (\ʁwa\) and RSF (\ɛ.ʁɛ.sɛf\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 47923, derived from the frequency rank of both members and their visual similarity.

roy is recorded at frequency rank #3,220, classified as anoun, pronounced \ʁwa\. RSF is at rank #44,703, tagged as anoun, pronounced \ɛ.ʁɛ.sɛf\.

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 47923, this pair ranks #183,065 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of roy vs RSF

Shared letters: r. Private to "roy": oy. Private to "RSF": fs.

"roy" · 3 letters · shape CVV  ·  "RSF" · 3 letters · shape CCC

Frequently Asked Questions

Can "roy" and "RSF" be used interchangeably?
No. They are said differently (\ʁwa\ versus \ɛ.ʁɛ.sɛf\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
In ordinary French text, does "roy" or "RSF" show up more?
"roy" is the more common of the two: it sits at frequency rank #3,220 in our French list, against #44,703 for "RSF". That is a wide gap, so in ordinary text the rarer spelling is the one worth double-checking.

What to do next

Eye-level mix-up between "roy" and "RSF" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "roy" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "RSF" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #183,065 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "roy" and "RSF" also get mixed up with nearby pairs, the highest-scored neighbour is "rog vs RSF". Nearby pair

Confusion rank #183,065 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list