1.**Developers implementing phrase generation or checksum verification must separate words using ideographic spaces / accommodate users inputting ideographic spaces.**
1. Words can be uniquely determined typing the first 4 characters (sometimes less).
2. Special Spanish characters like 'ñ', 'ü', 'á', etc... are considered equal to 'n', 'u', 'a', etc... in terms of identifying a word. Therefore, there is no need to use a Spanish keyboard to introduce the passphrase, an application with the Spanish wordlist will be able to identify the words after the first 4 chars have been typed even if the chars with accents have been replaced with the equivalent without accents.
3. There are no words in common between the Spanish wordlist and any other language wordlist, therefore it is possible to detect the language with just one word.
5. No pronouns, no adverbs, no prepositions, no conjunctions, no interjections (unless a noun/adjective is also popular than its interjection like "mince;chouette").
6. No numeral adjectives.
7. No words in the plural (except invariable words like "univers", or same spelling than singular like "heureux").
8. No female adjectives (except words with same spelling for male and female adjectives like "magique").
9. No words with several senses AND different spelling in speaking like "verre-vert", unless a word has a meaning much more popular than another like "perle" and "pairle".
10. No very similar words with 1 letter of difference.
11. No essentially reflexive verbs (unless a verb is also a noun like "souvenir").
12. No words with "ô;â;ç;ê;œ;æ;î;ï;û;ù;à ;ë;ÿ".
12. If 3 of the first 4 letters are already used in the same sequence in another mnemonic word, there must not be the same sequence of 3 or more letters.
Rules 11 and 12 prevent the selection words that are not different enough. This makes each word more recognizable among others and less error prone. For example: the wordlist contains "atono", then "atomo" is rejected, but "atomico" is good.
2. Words can be uniquely determined typing the first 4 letters.
3. Only words containing all letters without diacritical marks. (It was the hardest task, because in one third of all Czech letters has diacritical marks.)
7. Words are sorting according English alphabet (Czech sorting has difference in "ch").
8. No words already used in other language mnemonic sets (english, italian, french, spanish). Letters with diacritical marks from these sets are counted as analogous letters without diacritical marks.