it is to be understood that the following disclosure provides many different embodiments , or examples , for implementing different features of various embodiments . specific examples of components and arrangements are described below to simplify the present disclosure . these are , of course , merely examples and are not intended to be limiting . in addition , the present disclosure may repeat reference numerals and / or letters in the various examples . this repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed . when stressing post - tensioned concrete members , anchoring systems may be provided to hold the post - tensioning tendon both before and after stressing . in some embodiments , as depicted in fig1 a - b , post - tensioning tendon 11 may be positioned within concrete element 21 . post - tensioning tendon 11 may include for example and without limitation fixed end anchor 13 , tension member 15 , and stressing end anchor 17 . in some embodiments , post - tensioning tendon 11 may also include a sheath ( not shown ) positioned about tension member 15 and one or more seals ( not shown ) between the sheath and each anchor . the sheath and seals may , for example , protect tension member 15 from corrosion after concrete 23 ( shown in fig1 b ) is poured . additionally , the sheath and seals may , for example , prevent concrete from ingressing into tension member 15 and preventing or retarding its tensioning as discussed below . in some embodiments , a seal for fixed end anchor 13 may be omitted . as depicted in fig1 a , in some embodiments , fixed end anchor 13 may be positioned within concrete element 21 such that it will be completely encased in concrete 23 . in some embodiments , fixed end cap 19 may be positioned at the end of fixed end anchor 13 to , for example , protect tension member 15 from corrosion after concrete 23 is poured . stressing end anchor 17 may be positioned within concrete element 21 such that it is substantially surrounded by concrete 23 . pocket former 25 may be positioned between the end of stressing end anchor 17 and concrete element 21 . pocket former 25 may be adapted to , for example and without limitation , prevent concrete 23 from filling the space between stressing end anchor 17 and the edge of the resultant concrete member formed by concrete 23 within form 21 . pocket former 25 may thus allow access to tension member 15 from without the concrete member once it is sufficiently hardened and concrete element 21 is removed . in some embodiments , as depicted in fig1 c , pocket former 25 may include pocket former body 27 . in some embodiments , pocket former body 27 may include a coupler ( not shown ) for coupling pocket former 25 to stressing end anchor 17 . in some embodiments , pocket former body 27 may be generally hollow . as depicted in fig1 c - e , pocket former body 27 may be frustoconical . in some embodiments , by tapering pocket former body 101 inward from the edge of concrete 23 , removal of pocket former body 27 from concrete 23 may , for example and without limitation , be accomplished more easily . as depicted in fig1 d , when pocket former body 27 is removed from concrete 23 ( once concrete 23 has reached a sufficient strength ), cavity 27 ′ is left in concrete 23 corresponding with the outside shape of pocket former body 27 . in some embodiments , once pocket former body 27 is removed from concrete 23 , tension member 15 may be placed under tensile stress . in some embodiments , stressing end anchor 17 may be adapted to allow tension member 15 to extend in length and be stressed against fixed end anchor 13 ( now embedded in cement 23 ), while preventing retraction of tension member 15 once stressed . in some embodiments , tension member 15 may be cut to length such that it does not , for example , extend beyond the edge of concrete 23 . in some embodiments , once sufficient tension has been applied , cavity 27 ′ may , as depicted in fig1 e , be filled with filling material 29 . filling material 29 may , as understood in the art , be grout , a cementitious chloride - free grout , or concrete . in some embodiments , permanent stressed end cap 101 may be installed over the end of tension member 15 to , for example and without limitation , prevent filling material 29 from entering stressed end anchor 17 and tension member 15 . in some embodiments , permanent stressed end cap 101 may include cap body 103 . cap body 103 may be generally cylindrical in shape , although one having ordinary skill in the art with the benefit of this disclosure will understand that cap body 103 may be any shape . in some embodiments , cap body 103 may be generally hollow , allowing cap body 103 to fit over the end of tension member 15 . in some embodiments , cap body 103 may be filled with grease . in some embodiments , permanent stressed end cap 101 may include coupler 105 adapted to couple permanent stressed end cap 101 to stressed end anchor 17 . coupler 105 may include , for example and without limitation , a threaded connection , press - fit connection , bayonet connection , or any other suitable coupler for coupling permanent stressed end cap 101 to stressed end anchor 17 . in some embodiments , one or more seals ( not shown ) may be included to , for example , fluidly seal between stressed end cap 101 and stressed end anchor 17 . in some embodiments , coupler 105 may be a separate part from stressed end cap 101 and installed to stressed end cap 101 and stressed end anchor 107 after stressed end cap 101 is in position . in some embodiments , as depicted in fig1 e , permanent stress end cap 101 may include a grout retention feature 107 . grout retention feature 107 may provide more surface area and / or one or more locking features into which filling material 29 may fill , thus , for example and without limitation , preventing filling material 29 from delaminating or otherwise coming loose from or moving relative to concrete 23 . as depicted in fig1 e , in some embodiments , grout retention feature 107 may extend past the end of cap body 103 . as depicted in detail in fig3 , grout retention feature 107 may be coupled to cap body 103 by , for example and without limitation , neck 109 . in some embodiments , grout retention feature 107 may be generally rounded or toroidal in shape as depicted in fig1 e , 3 . in some embodiments , as depicted in fig2 a , 2 b , grout retention feature 207 may be generally polygonal in shape . one having ordinary skill in the art with the benefit of this disclosure will understand that grout retention feature 107 may have any shape suitable for retaining filling material 29 within cavity 27 ′, and may include without limitation , round , square , polygonal , mushroom - shaped , toroidal , ellipsoidal , spherical , or prismatoidal . in some embodiments , as depicted in fig4 , grout retention feature 307 may include one or more locking features . in some embodiments , locking features may include , for example and without limitation , textured surfaces , ridges , grooves , recesses , or protrusions from or into grout retention feature 307 adapted to prevent movement of filling material 29 relative to concrete 23 . for example , fig4 depicts multiple protrusions 309 extending from grout retention feature 307 . one having ordinary skill in the art with the benefit of this disclosure will understand that protrusions 309 from grout retention feature 307 may be of any shape , including but not limited to , cylindrical , prismatoidal , ellipsoidal , or any combination thereof . in some embodiments , grout retention feature 307 may further include a surface texture ( not shown ). one having ordinary skill in the art with the benefit of this disclosure will understand that the surface texture may be any pattern including but not limited to cross hatched , grooved , stippled , ridged , knurled , fluted , or any combination thereof . the surface texture may be formed as protrusions from grout retention feature 307 , as depressions into grout retention feature 307 , or any combination thereof . in some embodiments , as depicted in fig5 , grout retention feature 407 may be formed as an integral part of cap body 103 . the foregoing outlines features of several embodiments so that a person of ordinary skill in the art may better understand the aspects of the present disclosure . such features may be replaced by any one of numerous equivalent alternatives , only some of which are disclosed herein . one of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein . one of ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure and that they may make various changes , substitutions , and alterations herein without departing from the spirit and scope of the present disclosure .