The IRLI has decided to use the Latin character æ in place of the two letter combination ae used by the Catoena ih'Swaet Doaege Rihanai to transliterate the single letter of the Rihan alphabet that has the sound "ay." This decision has been made for the sake of clarity. Æ is visually one letter to English readers, and using ae to transliterate it into English, while not wrong in itself, presents many opportunities for confusion. English readers are much more likely to incorrectly think of æ as a two-letter diphthong instead of a one letter sound if it is transliterated with ae.
Even the Catoena ih'Swaet Doaege Rihanai website makes this mistake in several places. An example is in the CSDR's description of the noun derivative la- ... -(e)ri, which is used to create a noun that is the object of a root verb, e.g. larhudheri, "employee," from the verb rhudh, "to employ, to use." They show the e of the derivative in parenthesis and explain that it is dropped if the verb root ends in e or a.
Dropping the e makes sense if the verb root ends in e also, as that would create long vowel. The e is unnecessary. Dropping the e though if the verb root ends in a is undoubtedly a mistake made due to thinking in English rather than Rihan.
Let's use the example of the verb iera, "to arrest." Using the CSDR rule, when we form the object noun, which would basically mean "arestee," or "someone who has been arrested," we would drop the e and create the new word laierari. If we didn't drop the e, we would get laieraeri, which in the model of using ae and thinking in English, would cause the ae in the word to be thought of as the sound for æ (ay) rather than as the two separate sounds of a and e (ah-eh). Using the character æ to transliterate the sound of "ay" would eliminate that problem, as visually the English reader would distinguish it as one letter instead of two. Thus, there would be no need to drop the e of the noun derivative. Laieraeri and laieræeri would be easily recognizable as two different sounding words.
This also eliminates the need to use a glottal stop to distinguish between the ae as one sound and ae as two sounds. Under the CSDR system, laieraeri would be laiera'eri. This produces a false pronunciation, as the glottal stop is an actual sound and letter in the Rihan alphabet. It should not be used as a marker to designate the difference between two other sounds.
This change in transliteration will require some relearning for those of us who are familiar with and have been using the CSDR method over the years. It is a change needed to clarify the language, though, and it best serves the growth of Rihan moving forward. Those newly-interested in Rihan will benefit most of all. It will be one less confusing hurdle for them to jump.
The change will also affect some portions of the grammar and will greatly affect the dictionary. The dictionary will be gradually changed over to the new model, as time permits, but the old CSDR method of spelling will be retained as an alternate, so searching will be kept easy for those with keyboards that don't allow them to easily type æ.
There is also nothing wrong with writing or typing ae in place of æ when using Rihan. It will still be understood. It isn't always easy to print æ. The change is for clarity of grammar and pronunciation as displayed on the IRLI website, though using æ will benefit the clarity of your own use of Rihan to others also.
Wikipedia has an article explaining the Latin character æ, which includes several methods available to type the character on a computer: http://en.wikipedia.org/wiki/%C3%86