Clothing (also known as clothes, apparel and attire) is a collective term for items worn on the body. Clothing can be made of textiles, animal skin, or other thin sheets of materials put together. The wearing of clothing is mostly restricted to human beings and is a feature of all human societies.
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A woman in presence of non-mahram must cover all her body except face and hands(wrists down) -even feet- with loose clothes so that the body shape shall not be seen underneath the clothes.
So Abayah or Chador is not mandatory.
According to Ayatullah al-Khu`i: Wearing a dress made of 100% silk is haram for men at all times.
However, he says: "There is no problem in carrying it [an item made from 100% silk] in salat and outside salat or in using it as bed-sheet or mantle --- as long as these items are not identified as `dress'.
"And there is no problem in making the hem of dress with it [100% silk] although it is ihtiyat wajib that the hem should not be more than four fingers in width.
"And there is similarly no problem in using it [100% silk] for waist-band...lace/braid...even the inner-linning of suits, etc.
"But a dress (libas) which is not sufficient [by itself for appropriate covering] in salat, then it is ihtiyat wajib to refrain from it." (Minhaju 's-Salihiyn, vol. 1, p. 139)
& ** In both these cases, Ayatullah Sistani says it is ihtiyat mustahab, not wajib. (Minhaju 's-Salihiyn, vol. 1, p.179)
In the light of the above, the use of a dress with pocket square would be allowed. About the neck-tie, I am still not sure how we would classify it -- as an item of dress or a decorative part of it?