The medieval spelling of Portuguese was not uniform, since it had no official standard, but most authors used an essentially phonemic orthography, with minor concessions to etymology common in other Romance languages, such as the use of c for /ts/ before e or i, but ç otherwise, or the use of ss for /s/ between vowels, but s otherwise.
The new standard became official in Portugal and its overseas territories at the time, which are today the independent nations of Angola, Cape Verde, Guinea-Bissau, Mozambique, São Tomé and Príncipe, and East Timor, as well as the Chinese S.A.R.
On the other hand, considering that the period of Galician-Portuguese troubadorian poetry had been a golden age of Portuguese literature, they aimed to keep the new orthography as close to the medieval spelling as possible, in spite of some phonetic changes which the language had undergone.
[citation needed] The resulting orthographic standard was essentially a compromise between these intents, on one hand, and common traditions, on the other: in a few cases, spelling conventions which went against etymology but had long become customary were made official.
Initially, the orthographic system, both in Brazil and Portugal, determined the usage of diacritics in cases where two words would otherwise be homographic but not homophonous, such as acôrdo, "agreement", distinguishing it from acórdo, "I wake up".
The orthography set by the 1911 reform is essentially the one still in use today on both sides of the Atlantic, with only minor adjustments having been made to the vowels, consonants, and digraphs.
Since then, the only remaining significant differences between the two standards, and only substantial changes addressed in the 1990 spelling reform, were in the use of diacritics and silent consonants.
In the decades that followed, negotiations were held between representatives of Brazil and Portugal, with the intent of agreeing on a uniform orthography for Portuguese, but progress was slow.
Notwithstanding its traces of etymology, the 1911 orthography aimed to be phonetic in the sense that, given the spelling of a word, there would be no ambiguity about its pronunciation.
The trema was also used in the words where the letter u is, exceptionally, pronounced in the digraphs gue, gui, que, qui, rather than silent as usual; e.g. agüentar, sagüim, freqüente, eqüidade.
But in Brazilian Portuguese both words in each example are pronounced the same way, so the grave accent is not used: pregar /e/ "to nail/to preach", molhada /o/ "wet/bundle"; the intended meaning is inferred from context.
Due to differing pronunciations, Brazilian spelling has a, ê or ô in several words where the European orthography has, respectively, á, é or ó.
In 1990, an orthographic agreement was reached between the Portuguese-language countries with the intent of creating a single common orthography for Portuguese.
In Portugal, the reform was signed into law by the President on 21 July 2008, allowing for a six-year adaptation period, during which both orthographies co-existed.
The legality of this decision is questioned, as the main bases of the International Treaty that governs the application of the new spelling reform are yet to be established, chiefly the common vocabulary drawn by all participating countries, that still does not exist.