1.1 Spell in Filipino except in the following cases:
1.1.1 Proper Noun. Example: Shih Huang Tih, Washington Circle, Shinjuko, Czech, National Basketball Association, Halili Beer, Victoria Peak.
1.1. 2 Technical or Scientific Words. Example: carbon dioxide, chemotherapy, green house effect, pizzicato, sodium glutamate, varicose, x-ray
1.1. 3 Words that have special cultural connotation. Example: bolshoi, feng shui, geisha, gourmet, jazz, joie de vivre, kibbutz, mardi gras, pizza
1.1. 4 When deviating from the original spelling will make the word look awkward or funny if spelled in Filipino. Example: jeywoking (jaywalking), "rendevu" (rendezvous), "saykayatrist" (psychiatrist), "klu" (clue), "Oderv" (hors d'euvre), "feris wil" (ferris wheel), "pastits" (pastiche), "montadz" (montage).
1.1. 5 The original spelling is well-known. Example: coke, duty-free, faux pas, fax, file, jai alai, jogging, mall, shabu, shopt, x-rated
1.2 In spelling borrowed words in English that contains the 11 vowel sounds, choose the nearest sound in Filipino. Example: drayb (drive), geyt (gate), istandardiseysiyon (standardization), layt (light)
1.3 Separate the borrowed words from the Tagalog prefix using a hyphen. Example: mag-delete, i-delete, nag- hot oil, i-salvage, mag-email-han. Avoid the affix within the word if the foreign words are being used as verbs, and do not change the spelling. But if this can't be avoided, spell the borrowed words in Filipino. Example: dumelit, hinat-oyl, sinlaveyds, inimeyl.
2.1 Use the letters F, J, V and Z for newly borrowed words and spell in Filipino. Example: forum, futbol, (from Spanish), jet, javelin, visa, varayti, ziper, zigzag
2.1. 1 Use the letters F, J, V, and Z when spelling indigenous Filipino words which carries these sounds. Example: Ifugao, Ivatan, Laji, vihud, zakat [old Tagalog alphabet focused on the Tagalog region]
2.1. 2 There's no need to use the letters F, J, V, and Z for words which have long been spelled using the 20 letters of the original alphabet (abakada). Example: alpabeto (Alfabeto), bapor (vapor), baso (vaso), birhen (virgin), bisyon (vision), dyaket (jacket), dyambol (jump ball), dyanitor (janitor), dyip (jeep), dyunyor (junior), opisyal (oficial), piyansa (fianza), pondo (fondo), pormal (formal), sapatos (zapatos), sapiro (zafiro), sarsuwela (zarzuela). Important guides for words spelled using the original abakada are the dictionaries written by Jose Villa Panganiban and Vicassan.
2.1. 3 There's no need to use the letters F, J, V and Z [in new Tagalog Alphabet] for derivative words or words which have come from a long-borrowed word. Example: rebisyon (revision), because this only sprung from the word "bisyon", pormalismo (formalismo) which is from "porma" / "pormal"
2.2 Use J only for newly borrowed words that has this letter and sound (dyey). Example: jam, jar, judo, juniper, jinggel (jingle), jornal (journal), jakpat (jackpot), hayjak (hijack)
2.2. 1 J is not used in words borrowed from Spanish which has the letter J, but has the sound of H. Example: kahon (cajon), hardin (jardin), hawla (jaula), hepe (jepe), heringgilya (jeringuilla), hustisya (justicia)[old Tagalog alphabet accomodated these sounds]
2.2. 2 J is not used in words borrowed from English which has the letter G, but has the sound of J. Instead, use DY based on the former abakada-rule in such cases. Example: adyenda (agenda), badyet (budget), dyenereytor (generator), dyin (gin), madyik (magic), mardyin (margin). When in doubt, one alternative is to use a synonym derived from Spanish. Example: use "heneral" (from the Spanish word "general" for "Heneral Garcia" instead of "dyeneral" (sounds like the English word general; use the Spanish "henerico" (generico) instead of "dyinerik" (English-generic); use the Spanish "heograpiya (geografia) or "heolohiya" (geologia) instead of "dyiyografi" (as in the English geography, or "dyiyolodyi" (geology)
2.3 Use C, Q, N (ene) and X [in New Tagalog Alphabet] for borrowed words that does not need a change in spelling. Example: cable, cinema, El Nino, exit, cono, manana, nina bonita, quarter, quartz, queen, status quo, tax, taxi, techno, telex, x-ray.
2.3 1 When the borrowed words are spelled in Filipino, C becomes S or K, based on how this is pronounced in the language [using the old Tagalog alphabet]. Example, kontrol (control), kontemporari (contemporary), korni (corny), korona (corona), korporal (corporal), kudeta (coup d'etat), asido (acido), saykel (cycle), sigarilyo (cigarillo), silinder (cylinder), sinico (cinico), sipres (cypress), sirko (circo), siyudad (ciudad).
2.3. 2 When the borrowed words are spelled in Filipino, the letter Q becomes KW (KUW) or K based on how it is pronounced in the language. Example: eskema (esquema), keso (queso), kerida (querida), kilo (quillo), kimika (quimica) kinse (quince), kinta (quinta), kinteto (quinteto), kwintuplet (quintuplet), iskuwad (squad), iskuwirel (squirrel)
2.3. 3 The letter N (ene) [old Tagalalog alphabet has this letter] becomes NY when the borrowed word is spelled in Filipino. Example: banyo (bano), kanyon (canon), donya (dona), pinya (pina), senyora (senora).
2.3. 4 The letter X becomes KS when the borrowed word is spelled in Filipino. Example: boksing (from the Spanish Boxear), eksibit (exhibit), eksodo (exodo), ekspedisyon (expidicion), eksperimento (experimento), eksperyensiya (experiencia), ekspres (express), ekstra (extra), leksikograpiya (lexicograpia), mikser (mixer), taksonomiya (taxonomia), teksbuk (textbook), teksto (text), seks (sex), seksuwal (sexual)